The Skeleton Key (2005)

Caroline Ellis (Kate Hudson), a good-natured nurse living in New Orleans, quits her job at a hospice to work for Violet Devereaux (Gena Rowlands), an elderly woman whose husband, Ben (John Hurt), is in poor health following a stroke. When Caroline begins to explore the couple's rundown Bayou mansion, she discovers strange artifacts and learns the house has a mysterious past. As she continues to investigate, she realizes that Violet is keeping a sinister secret about the cause of Ben's illness.