The Terror, based on a 1938 Edgar Wallace play, owes quite a bit to the Old Dark House genre so popular at the time.
It starts with a daring gold robbery. Later two of the thieves (including the great Alastair Sim) think they've been cheated. Then there's a series of murders at a country house.
A lighthearted mystery romp. Lots of fun.
My review: https://dfordoom-movieramblings.blogspot.com/2016/08/the-terror-1938.html