So You Want to Be in Pictures (1947)

Joe McDoakes (George O'Hanlon) decides he wants to be an actor. After a few at home lessons - he come out speaking in a French accent like Charles Boyer - he heads off to the studio after arranging an interview with director Anthony Anguish. His first mistake is to walk on to the set while they are filming and then his take on the role leads to director to walk off the set in despair. He finally gets a role, but it's not quite what he expected a Hollywood career might be.