Inner Sanctum was a rather large media franchise: Simon and Schuster had their mystery novels, there was a series of movies, a television series, and a series of films starring Lon Chaney Jr. But my favorite iteration is the old-time radio show, hosted originally by the creepmeister Raymond Edward Johnson. That's him up top there.
My favorite story about the show can be found on Wikipedia, but I've heard it from elsewhere as well: the creaking door isn't a door at all...the effect was provided by a squeaky desk chair. At one point, someone mistakenly oiled the chair, removing its ability to creak--and the foley guy had to just mimic the sound himself. Nice.