I have an odd question that maybe you can help me with. The house I just purchased has a small plastic box mounted to the base board molding in one of the rooms and the box connects to the furnace at the same spot that the thermostat does. The box is square, made of plastic and measures 2 inches by two inches. There is a one inch by one inch square raised section in the center of the box on one side. The 1x1 square section has a contact hole in each corner while the 2x2 flat area has two larger contact holes diagonally opposite of one another. There is noting mounted to the box, although it looks as if it is made for something to connect to it. Also I unscrewed the box (single Philips screw located on the back of it) and inside there is a spring and two colored wires that look like the ones inside a phone jack. I am curious what this is and if it is something that is being used by the furnace.