ID yet another movie

Hi all. New guy here. There was a tv (I think) movie in the '70s about 2 old ladies living in a house. One was an invalid in a wheelchair. The house had an elevator, and as I remember, the lady fell in, or was pushed down the shaft by the other sister’s lover. Anyway the spirit of the dead woman haunted them after that. Sorry that’s all I remember but I’d love to hear your ideas on the title. My brain hurts