Champagne for Caesar (1950) on Netflix

Plot summary

Beauregard Bottomley lives in Hollywood with his sister Gwenn, a piano instructor, and knows a great deal about every subject, yet he cannot hold a job. An employment bureau representative urges him to try for a job at the Milady soap company, whose eccentric owner, Burnbridge Waters, dislikes his humor and intellect and turns him down. Beauregard and Gwenn had seen Masquerade for Money, the quiz show Happy Hogan hosts and Milady sponsors, in which a contestant's costume sets the type of questions and each correct answer doubles the prize. For revenge, Beauregard appears on the show dressed as an encyclopedia, answers the questions easily, earns $320, declines the prize and suggests he return the next week. Waters invites him back for one question on each of six shows as a publicity stunt.