Shock (1977)

Dora Baldini, her husband Bruno, and her son Marco move to a huge house that belongs to her; she used to live there with Marco and her former husband, a drug addict who committed suicide. The house has stood empty since then, and Bruno, a pilot, has decided that they should move in since it is close to the airport. Soon Marco is possessed by the ghost of his father and Dora is haunted by the house. She tells Bruno that they need to leave the house and she is afraid of her son, but he believes she's relapsing since she had a breakdown when her husband died. Why is the vengeful spirit seeking revenge?