En face (2000)

Jean and Michelle, a young, bankrupt couple are surprised to learn they've inherited the palatial townhouse of their landlord, Guillemet complete with mysterious housekeeper, Clémence who has to keep on. Photographs reveal that the dead man spied on the wife (their apartment window faces his townhouse) in various states of undress. The mysterious housekeeper starts leaving clues around the house that reveal to the husband that his wife may know more about the dead man than she is letting on and may have had something to do with his death.