One Body Too Many (1944)

Albert L. Tuttle (Jack Haley) is a life insurance salesman with terrible timing. Upon reaching the lavish estate of millionaire Cyrus J. Rutherford, Tuttle is informed by the eerie butler, Murkil (Bela Lugosi), that his prospective client has recently died. In fact, Rutherford's relatives are gathered to hear the reading of his will. Soon, Tuttle is drawn into the strange brood's world of secret tunnels, odd portraits and a vanishing corpse -- all for an alluring niece (Jean Parker).