Walled In (2009)

Having finally secured her first assignment from her family's demolition business, Sam Walczak (Mischa Barton) is sent to supervise the destruction of an apartment house, only to discover a group of tenants still living in the condemned building. One such tenant, Jimmy (Cameron Bright), tells Sam an urban legend about a serial murderer who used to live in the building and entomb his victims in the walls. What's worse, the dead are believed to still harass the residents to this day.