The sleeper by Gillian White. Published by Open Road

Like many brides, Clover Moon is not happy that her mother in law has come to visit for the holidays. Violet is an opinionated bossy woman who takes delight at humiliating her daughter in law at every opportunity. Violet also claims to have a special talent, she is a medium who can talk to the dead. When Clovers husband finds the body of a woman floating in there cellar and a woman is missing from the local nursing home, Clover wonders if her mother in law and her spirits had something to do with the chaos.
A chilling gothic tale that will hold readers riveted.