Aatma (2006)

With her mother, Suman, father, and sister, Aarti, Neha leads a privileged life. She meets, falls in love with, and marries Dr. Aman Mehra of Life Care Hospital, while Aarti, an Intern at the same hospital, is in love with Police Inspector Siddharth and hopes to marry him soon. After celebrating their first wedding anniversary on the beach, Aman is confronted by a gun-toting couple who threaten him and demand that he sign a Death Certificate for a male named Avinash Malhotra, stating that he died of natural causes. They also give him a deposit and pledge to pay the balance after he completes the certificate. When Neha's life is threatened, Aman reluctantly prepares this text, little realizing that in doing so, the vengeful spirit of the dead male would manifest itself in Neha's body, forever changing their lives.