Lots more to look through as an advanced search in synopsys for museum finds 678 I did not check them all but here are some that sounded good. Only 64 when the new Keyword field is searched
I am going to post some as I found them that are available here or at CB+ for the later issues
I Love Lucy Comics (1954 series) #24 Changing Guards
Lucy and Ethel disguise themselves as palace guards to elude a London wax museum guard
Laugh Comix (1944 series) #46 Wilbur, Red and Linda go to the museum and get kicked out
Spook (1953 series) #30 Picture a Nightmare
A night guard at the museum is dragged into a painting presenting a door into a dimension of evil. He can fight his way back to the real world and manages to destroy the picture.
Mysterious Stories (1954 series) #7 The Statues!
When a museum is threatened to be closed down, the statues come to life and organize money by playing the stock market.
Slugger (1956 series) #1 No Ribbing Allowed
Slugger and the Little Wise Guys visit a museum but get kicked and head for the zoo.
Koko and Kola (1946 series) #2 Famous Statues Koko and friends visit a museum
Jackpot Comics (1941 series) #8 Maiden in Distress Clancy and Looney meet a mummy in a museum.
Hopalong Cassidy (1946 series) #14 Captain Tootsie's Counter-Spoo
Captain Tootsie foils a robbery in a museum by disguising himself as a mummy
Brides in Love (1956 series) #19 The Man I Married
Gorgeous Myra Sheldon could have had any man she wanted. No one can understand why she marries plain, shy Adam Maynard, a museum curator. But Myra had become tired of the party life. When Myra got to know Adam, she discovered someone who shared her secret desire for reading and thinking about life.
Beware! Terror Tales (1952 series) #6 Strange Friendship
Babylonian mummies come to life in a museum to fight age-old battles
The Beyond (1950 series) #13 Lure of the Sea Hag
Marine museum watchman Dick Collins gets involved in a tale of piracy and plunder. Following a mysterious witch/woman, he encounters undead pirates and their treasure. Collins survives, but all else is lost at sea.
True Tales of the Supernatural #17
"In the year 1926, John Buxton, a struggling young artist, was on a holiday trip in New England..."
At the local museum Buxton finds a portrait of a local painter looking exactly like him. He even painted the same motives
Baffling Mysteries #12
"The strange incident which is narrated below occurred in 1927, in the natural history museum of a large mid-western city..."
The curator gets killed by a "tribal death mask" falling from the wall. The mask had complained about being relocated from its home country earlier on.
Baffling Mysteries (1951 series) #5
Volcano of Vengeance
Tod Sloane, field man for the North American Museum, investigates Mount Pataxo, located in a small Central American country. In this volcano, an age-old but benign cult of godlike "goatmen" has survived. The superstitious locals want to sacrifice Sloane to prevent volcanic eruption. He is saved by the goatmen and their queen Arni. Sloane manages to disperse the locals superstition and wins a valuable artifact
America's Best Comics (1942 series) #25
Cleopatra's Comb
The caretaker of an Egytian museum commits murder and more in order to put away the infidel dogs who have desecrated the memory of Cleopatra
Adv Into the Unk 9
When the Shaman Walked(Table of Contents) comic story / 7 pages (report information)
Genre:horror-suspenseSynopsis:A night-watchman in a museum and his niece are protected from crooks by a statue of a Siberian Shaman.
All Good Comics (1944 series) #[nn]
The Bleeding Statue
The Puppeteer saves museum curator Dr. Martin's daughters when they are kidnapped by a mad sculptor.
Here are some stories not PD
The Natural History Mystery
6 pageThe Adventures of Jell-O Man and Wobbly (1991 series) #1
Mystery of the Disappearing Mummy
11 pages The Adventures of Little Archie (1959 series) #141
Adv Comics 211 Superboy's Most Amazing Dream
Clark dreams of life when he grows up to be Superman and works in the Metropolis Museum
Adv Comics 126 Riddle of the Rembrandt
Wes and Sandy, while visiting a museum, discover a fake Rembrandt hanging on the wall, so Wes offers to buy the piece from the curator. When this piece is stolen from the Dodd's residence, the Sandman discovers that a criminal artist has been hired to touch-up real Rembrandts, then buy them as fakes, thus benefiting the felon behind the scenes.
Abbott & Costello #12
The Spooky Past Cleaned-out Fast!
Abbott & Costello work cleaning up a museum.
Adventures Into Terror (1951 series) #17
The Vandals!
When four vandals enter a museum at night to cut off the gold heads from a hydra idol, they end with their heads placed upon the evil idol
Adventures of the Big Boy (1957 series) #206
In The Service of Art
Big Boy disregards the rules at the Louvre museum and gets into a fight with the security guards. But by pure luck, he traps an art forger so all is forgiven.
Not sure how odd you want to go
Alf Annual (1988 series) #3 Buy Low -- Shell High!
ALF shows a video of the time that he and the New Age Melmutant Abstract Turtles teamed to stop Censorhead from stealing works from the Museum of Melmodern Art.
All-Winners Comics (1941 series) #16
Dead Man's Shoes
Cap and Bucky come across the scene of a gang striping a dead man of his clothes, and soon learn that the murdered man is a night watchman at the Woolsey Museum, and that the gang was intending to strip the musuem of its art and jewel collections.
Mighty Comics (Archie, 1966 series) #50
The Web vs. Inferno, the Fire-Breather!
Irritated than John continues fighting crime as the Web, Rosie resumes her career and goes to work Tom Alexander, a museum curator. But Inferno sets art pieces on fire at the museum as the Web investigates. Then the real Inferno shows up and Tom reveals his true colors.
Archie (1962 series) #156
Getting Arty!
Li'l Jinx pratices her art by adding facial features to both posters around town and pictures in the museum.
Archie (1962 series) #578
The Zero Hero
Archie and Reggie convince Pop Tate to open the Riverdale Skateboard museum in order to bring in new customers. Unfortunately, Archie's part of the museum makes him look like a klutz, while Reggie's part makes him look like a champion.
Archie & Friends (1992 series) #69 Go Figure
The Pussycats visit a Rock n Roll museum and see the exhibit on their band.
Astonishing (1951 series) #49 From Out of the Past
Three paleontologists feel smug in their knowledge until they uncover a dig site that contains a museum constructed by prehistoric man that contains more fossil bones than they have ever gathered.
Barbie (1991 series) #52
Hope For Harmony
Skipper and Emily run into Andre performing in the park. They all go to the museum for Black History Month music exhibits.
Batman (1940 series) #238 Danger in the Totem's Eye
Al Pratt goes to a museum to research Indian culture but ends up tracking down some robbers.
Betty (1992 series) #165 Then and Now
Archie and Betty go to the Living History Museum, where they get to dress in period clothing and live like their ancestors did
Billy Batson & the Magic of Shazam! (2008 series) #13
On a field trip to the Fawcett City Museum, Mary and Billy meet Theo Adam, who has no memory of his former existence as Black Adam (except that he doesn't like Captain Marvel). He meets Freddy Freeman, who also doesn't like Cap, and accidentally speaks the name of the wizard, which immediately tranforms him into Black Adam.
Boris Karloff Thriller (1962 series) #2 The Smiling Cavalier
Laurie Callan loves to visit the museum and try to sketch the 17th century masterpiece "The Smiling Cavalier" but she never seems to be able to get it right. One night when she accidently remains in the museum after it closes the paintings come to life. The "Smiling Cavalier" (Don Juan) and the other two "Smiling Cavalier" paintings come out and chase Laurie until she can escape. The night guard that lets her out looks just like the Don Juan "Smiling Cavalier".
Four Color (1942 series) #257 Daze 'n' Knights
When Henry needs to hide from the bill collector he decides to take Iodine to the museum. The bill collector hears Iodine tell Sharkey that they are going there so he follows them. When he catches Henry he runs and hides in a suit of armor. After much destruction from running in the armor Henry is caught. Iodine has to break into her piggy jar to help pay for the damage.
Four Color (1942 series) #559 Child's Play
Lucy needs money to buy a dress for a party, so she fills in as caretaker for ten children on a Saturday. The group causes chaos in a museum.
The Fox and the Crow (1952 series) #102
Pharaoh Today, Cloudy Tomorrow!
On a trip to the museum, Spot tells Stanley about his life in ancient Egypt, where he modeled for the Sphinx and made an enemy of the Pharaoh, King Mut. It turns out that Mut's mummy is in the very same museum, and comes to life to continue his vendetta against Spot.
Ghost Manor (1971 series) #68 The Eye of the Cat!
A two-bit museum security guard steals two jewels from a cat statue and suffers the consequences