[TOMT][MOVIE][2000s] MOVIE ABOUT A STALKER LIVING IN HIS VICTIM’S WALLS

Movie about a stalker who ends up living in the walls of his victim’s house and attempts to kill her. I remember the movie abruptly ending when the person being stalked killed the stalker with a nail gun. The stalker had a gruff black beard and I remember the victim being short and blonde maybe as well as being some sort of fashion designer?. I watched it on a Spanish tv channel although i’m not sure whether that was the original language of the movie or not. Best of luck.