Session 9 (2001) on Netflix

The owner of a small asbestos abatement company, Gordon Fleming, needs to work and accepts to remove the asbestos of the abandoned Danvers State Hospital, a mental institution that is closed since 1985 in one week. He has a baby girl and has some personal problems with his wife Wendy, calling her on his cellular. Gordon and his partner Phil need to bring more workers to accomplish the schedule, and Hank, Mike and Jeff join the team. Phil does not like Hank that has stolen his girlfriend; Mike is a law school dropout; and Jeff has fear of the darkness. Mike finds a sealed box tagged with the word "Evidence" and when he opens, he finds nine taped sessions of the patient Mary Hobbes that had multiple personalities (The Princess, Billy and Simon). Mike listens to the tapes and none of the personalities wants to talk about Simon. However, in Session 9, Simon finally appears and he discovers that he is evil. Meanwhile Hank finds ancient silver coins and disappears.