The Evil Touch (1973)

Season 1: Episode 8

Upon returning home Roger Carlyle insists his wife Louise go take a look at something in their basement. What he neglects to tell her is that there are currently no stairs leading to the basement. Louise opens the basement door and falls to her death. Jenny, the Carlyle's maid, begins to blackmail Roger. Eventually Jenny's extortion drives Roger to plan ""accidents"" for himself, hoping to pin them on Jenny.