Mortuary (2005)

Recently widowed Leslie moves with her teenage son Jonathan and her young daughter Jamie to a small town in California with the intention of starting a new career as a mortician. When they arrive, Leslie realizes that the decrepit Fowler Brothers Funeral Home, she has purchased sight unseen, was in fact abandoned due to problems with the septic tank and a strange black mold contaminating the entire property. While Leslie does her best to clean the place up and get her business started, Jonathan gets a job at a local diner where he soon learns about the legend of Bobby Fowler, the deformed son of the Fowlers, who disappeared at age 8, and who local legend has it is still living somewhere on the mortuary lot...

Source: TMDb