I am new to the forum so thanks in advance for any advice. I have purchased the Maestro and two companion switches but when I read the directions I am confused. One of the switches has just three wires and the other two are identical but have TWO black screws and four wires (two red and two black). I am including pictures to help visualize. I am assuming that the one that is different is the middle (and where the Maestro Master should go?). The one with the three wires black screw wire goes over to the switch next to it....