AmagansettHenry Kessler said he mailed two checks to Compton Air Conditioning, both in the amount of $1,500, for work on a building in the Bronx on Sept. 8. They had cleared by Sept. 13, but the owner of the company said he had not received them. Mr. Kessler contacted his bank.East Hampton Squatters apparently have been living in a house on Three Mile Harbor Road that had been foreclosed and abandoned for several months. Sometime between Aug. 1 and Sept. 13, it appeared that people entered the house, spray-painted the walls, and made some holes in them.