Inner Sanctum debuts, January 1941.

Richard Widmark, left, gets
physical on the Blue Network.
NYPL

The Museum of Broadcast Communications notes that this month in 1941, the radio program Inner Sanctum (with a signature squeaking-door opening) debuted on the Blue Network (later ABC) with "The Amazing Death of Mrs. Putnam." The producer was Himan Brown, who went on to produce the CBS Radio Mystery Theatre and numerous other series. Several episodes of Inner Sanctum can be downloaded from the Internet Archive, including "Make Ready My Grave" starring Richard Widmark.