A Gem of a Jam (1943)
The stooges are janitors working in the offices of Doctors Harts, Burns and Belcher. Some crooks arrive seeking medical attention after their boss has been wounded in a shoot out with the cops. Mistaken for doctors, the boys are forced to operate on the wounded crook, but instead they accidentally dump him out the window into a passing police car. The rest of the gang chases them into a store room filled with dummies where the cops finally catch the bad guys.