In his monologue, Jack claimed that he was cutting costs by having Mary Livingstone run the spotlight. While it became a running joke during the episode, Mary was never actually shown on camera.
Benny first performed this parody of Gaslight (1944) with Barbara Stanwyck on the radio in October 1945. The January 1952 live TV recreation was so popular that they filmed it again in June 1953 to be shown during series 4. But a legal dispute with MGM prevented it being shown until series 9: Autolight (1959).