Immortal Spirit

Seven years ago undercover police officer Mike (Michael Wong) made the grave mistake of saying "I love you" to a thief he was tailing (Almen Wong). When a girl named Lily Wong, died in a bungled sting, the seeds of a vengeful ghost were sown. Fast-forward to 1999 Hong Kong and Lily finds her man breaking his mock-promise of undying love. Unimpressed, she assumes the body of an angry young cop to punish Mike and his family. (imdb)