From Wikipedia:

Inner Sanctum Mysteries was a popular old-time radio program that aired from January 7, 1941 to October 5, 1952. Created by Himan Brown, the anthology series featured stories of mystery, terror and suspense. The tongue-in-cheek introductions were in sharp contrast to shows like Suspense and The Whistler. A total of 526 episodes are known to have been produced.

The early 1940s programs opened with Raymond Edward Johnson introducing himself as, "Your host, Raymond," in a mocking sardonic voice. A spooky melodramatic organ score (played by Lew White) punctuated Raymond's many morbid jokes and playful puns. Raymond's closing was an elongated "Pleasant dreeeeaams, hmmmmmmm?" His tongue-in-cheek style and ghoulish relish of his own tales became the standard for many such horror narrators to follow, from fellow radio hosts like Ernest Chappell (on Wyllis Cooper's later series, Quiet, Please) and Maurice Tarplin (on The Mysterious Traveler) to EC Comics' Crypt-Keeper in various incarnations of Tales from the Crypt. In interviews, EC publisher Bill Gaines stated that he based EC's three horror hosts not on Raymond but on Old Nancy, host of radio's earlier The Witch's Tale (1931-38).

When Johnson left the series in May 1945 to serve in the Army, he was replaced by Paul McGrath, who did not keep the "Raymond" name and was known only as "Your Host" or "Mr. Host". (Berry Kroeger had substituted earlier for a total of four episodes). McGrath was a Broadway actor who turned to radio for a regular income. Beginning in 1945, Lipton Tea sponsored the series, pairing first Raymond and then McGrath with cheery commercial spokeswoman Mary Bennett (aka the "Tea Lady"), whose blithesome pitches for Lipton Tea contrasted sharply with the macabre themes of the stories, and who primly chided the host for his trademark dark humor and creepy manner.