The Nines (2007) on Netflix

Gary, an actor who plays a cop on television, uses too much lighter fluid when he burns his ex-girlfriend's things, then he drinks and drives, uses crack, and crashes his car. He sobers up in jail and is placed under house arrest and the watchful eye of a publicist, the cheery and tough-minded Margaret. She moves him into the empty house of a writer who's away in Canada on a shoot. Gary meets Sarah, an attractive and seemingly-willing neighbor. His friendship with Margaret blooms and strange things happen: he finds notes he doesn't remember writing, he hears noises, and he seems to bump into himself in the kitchen. Two remaining chapters reveal what's going on.