Where There's a Will (1936)

Will Hay plays the pennyless, bungling solicitor Benjamin Stubbins, who arrives at his office to find his insolent office boy (Graham Moffatt) with his feet up on the desk, reading a wild west magazine, which Hay confiscates so that he can read it later. Stubbins later takes a job from a group of Americans who claim they want him to track down some ancestors of theirs in Scotland. In reality however they want to use his office so they can rob a safe in the room immediately below his office. Stubbins takes the job (which is designed to keep him out of the office). In the end Stubbins realises his mistake and at a Christmas Eve fancy dress party he informs a group of carol singing policeman about the Americans nefarious activities

Unfortunately the movie Where There's a Will is not yet available on HBO Max.