Kaun? (1999)

A Young woman is at home alone and watches the news of a killer who is on the lurch, hears her doorbell ring and proceeds to answer it in caution. A man named Sameer Puranvale requests to meet Mr. Malhotra and requests her to open the door. The woman assumes him to be the killer, refuses to answer the door and lies to Sameer saying that her home is addressed to Mr. Gupta and not Mr. Malhotra. Sameer manages to enter her house but they get interrupted by the thief who claims to be a Police officer. Ultimately in a plan to escape Sameer stumbles upon the dead body of Mr. Malhotra and gets attacked by the woman who also kills the thief. In the end it is revealed that she is mentally ill as she hides the corpses and proceeds to answer another visitor who wants to meet Mr. Malhotra.