TRUCK WAS PARKED ON A 14 DEGREE INCLINE WITH ENGINE FACING UPHILL AND THE 4WD WAS IN 4WD-LOW. WITH NO ONE IN THE TRUCK AND AFTER 5010 MINUTES, TRUCK DISENGAGED FROM PARK. THE TRUCK PROCEEDED DOWN THE HILL CAUSING THE DRIVER TO JUMP OUT OF WAY FROM BEING HIT. THE TRUCK CAME TO REST AFTER HITTING THE SIDE OF A HOME. POLICE WERE CALLED TO INVESTIGATE THE ACCIDENT.