Scrambled Brains(1951)

Shemp is a sick man, suffering from hallucinations. His worst vision is that his ugly nurse Nora is actually beautiful. When Moe and Larry come to take him home from the sanitarium, they discover he's become engaged to Nora. On the way to Nora's apartment for the wedding, the boys get in a fight with a stranger who promises to get even with them if he ever sees them again. They arrive to finding Nora waiting for her father, who, when he arrives, turns out to be the man they just fought with.