Bud Abbott and Lou Costello Meet the Killer, Boris Karloff (1949)

Lost Caverns Resort Hotel bellhop Freddie Phillips gives an empty threat to one attorney Amos Strickland, and is shortly fired. When Freddie visits his guest's suite to apologize, he finds Strickland dead of a gunshot wound. As the investigators file in, Freddie becomes the scapegoat of the guests in the hotel, who all had a bone to pick with Strickland. It's now up to Freddie and Detective Casey Edwards to find out who the real killer is, all the while avoiding the many vigorous and violent villains staying at the resort.