Hush... Hush, Sweet Charlotte

This is the tale of a wealthy southern spinster Charlotte Hollis (Bette Davis) who lives with her eccentric maid (Agnes Moorehead) in a decaying southern mansion, shunned by the townsfolk after the mysterious axe-murder of her late lover. When her jealous cousin (Olivia de Havilland) and her cousin's wily husband (Cotton) arrive for a visit, the two conspire to drive Charlotte insane and have her committed so the two can sell off her estate and pocket the proceeds. (official distributor synopsis)