These are all based on pulp/radio prototypes I believe.
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The radio weird-mysteries definitely predated the EC stories of 1950 onward.
Someone mentioned the Witch's Tale [yes, an excellent series]...there were many others--Inner Sanctum, Arch Obler's Lights Out [I think that was his]...and several others I have on my hard drive.
The distinction I can see having read the EC's and having heard many of the radio shows over the past few years is that the EC stories seemed to connect the "commupence" to the "crime" more directly than the radio stories seemed to do...which I think is the twist ending trademark of the EC stories. The main writer of those EC tales has mentioned the influence of radio in various interviews [though I don't think he mentioned the shows by name].
I'll be listening to one of these radio shows and think "this is like an EC story [in tone]"--then the ending is nothing like an EC story. So the connection between the two is lost. EC went a step further as far as I can tell. They had definitely crafted a kind of formula that was pure EC.
Many of the radio shows are good--as are Old Time Radio Shows in general--before there was TV there was the theatre of the mind. I work as a comics freelancer all day at the computer and I listen to this stuff rather than have the TV on [No turning of my head to see the picture--with radio, there IS no picture].
You can download a TON of these shows, in addition to comics-related Radio titles, detective shows, Sci-Fi, westerns, etc..at Zootradio.com [I think it is].
Some of the best overall shows are Gunsmoke, Dragnet, and The Saint. Wonderful stuff. Not supernatural, but really good radio entertainment. The supernatural shows vary in story quality from show to show, season to season. Some very, very good to just plain odd, depending on the show title. Same for the Sci-Fi shows.
You can buy collections on ebay, too.
Moondood