Unfortunately from what I can tell is isn't, the garage light only has black/white/ground for the lights, and then black/white/ground going back to the disconnected switch. The garage lights are wired as expected, black connected together and white connected together. The garage was an addition in the 90's(house is from the 70's). If I had to guess that light switch controlled a light that was on the other side of the wall, now a garage.