The Lucy Show (1962)

Season 5: Episode 12

Lucy is overworked, between the work that she's neglected and having to sell tickets for a benefit for the bank. Mary Jane warns that Lucy will have a nervous breakdown if she's not careful, but Lucy initially blows off this comment -- but she later thinks she's been hallucinating when she enters Mr. Mooney's office and finds a monkey, who's part of the benefit show, sitting at Mooney's desk. Lucy thinks she's been seeing Mr. Mooney as a monkey, so it's off to the psychiatrist's office, who gives her this advice: ""Face your fear and it will disappear."" So on her next encounter with the simian, she treats him as if he's Mooney... which gets confusing as Mooney and the monkey simultaneously enter and exit the room...