On July 24, 1993, about 1135 eastern daylight time, a Piper PA-28-140 airplane, N95478, experienced partial loss of engine power during climb from takeoff at Sparta, Michigan, and landed short while attempting to return to the airport. The private pilot and two passengers reported no injury. The airplane was substantially damaged. Visual meteorological conditions existed in the vicinity. The local, personal flight originated about 1130 without a flight plan and operated under 14 CFR 91. The pilot stated he had climbed about 550 feet above field elevation when the engine began to run rough and engine revolutions fell from 2350 to 1500 rpm. He turned back toward the airport and unsuccessfully attempted various means to clear the engine. The airplane landed short of the runway in a construction yard and struck a pole. Examination of the airplane revealed a dislodged landing light gasket caught in the airbox screen and trailing into the carburetor as far as the throttle plate.