Tinseltown(1999)

On a Christmas Eve in Hollywood, would-be screenwriters Tiger and Max are arguing about whether Tiger should give up and hop on the next bus home. Max convinces his partner to hang around for at least a few more days to try to sell their script. Only problem is they have nowhere to stay. So they break into the building where Tiger stored his belongings and camp out, while Cliff, the building manager, allows them to stick around on a short term basis. The next day, they find out that their script is not commercial enough, and Max discovers that Cliff is the Costume Killer, a serial murderer. Max hits upon the idea of making Cliff the central character in a new script.