The Lucy Show - Season 5 - Episode 12 - Lucy and the Monkey

Mary Jane warns Lucy that the long hours she's putting in at the office could lead to hallucinations. Later, when she a monkey appears and apparently disappears in Mr. Mooney's chair, she begins to think she's loosing her mind and consults a psychiatrist. Creators: Bob Carroll Jr., Madelyn Davis, Bob Schiller Starring: Lucille Ball, Gale Gordon, Vivian Vance, Jimmy Garrett, Sid Gould, Ralph Hart