I was in grade school in Boston and caught CBS Radio Mystery Theater on WEEI. It came on every night at exactly 10:07. Apparently there were 1400 episodes made. I see John Lithgow, Sarah Jessica Parker and Fred Gwynne among other famous voices on the Wiki page. It’s funny that I can’t really remember any plots but I do remember a lot of coffee and pain medication commercials.
LOL I remember several. The one I remember best was, the adaptation from Poe’s Cask of Amontillado. It was SPOOKY!