The engine lost power while on final approach after the 1,353-hour commercial pilot selected an empty fuel cell during the landing check. The pilot reported that he completed the landing checklist and was cleared to land on Runway 31. While approximately 5 miles out on final approach, the pilot was instructed by approach control to fly magnetic heading of 280-degrees for a right base for Runway 04R. The pilot reported that as he performed his GUMPS check (gas, undercarriage, mixture, propeller, and switches), he moved the fuel selector from the left tank to the right tank. The pilot added that at this point, the engine started losing power. The pilot then moved the fuel selector back to the left side to no avail. The pilot declared an emergency and informed the control tower that he would be landing at a nearby football field. About 500 feet short of the intended landing site, the airplane's right wing clipped a tree. The airplane then came to rest in a residential area, with the right wing on top of a house and the left wing on an automobile approximately 2 nautical miles short of the destination airport. The wings and fuselage sustained structural damage. The engine and propeller were also damaged. The FAA inspector, who responded to the site, found that the airplane's fuel selector was not in the left indent position. Five gallons of fuel was drained out of the left fuel tank.