Ken , even if those switches were for future use, the other end should , by code , terminate in a junction box. A switch near a doorway could operate a wall outlet to plug a floor lamp into. I'd start by testing all the plugs in the room with the switches in one position then the other. Then open any ceiling outlets and do the same. But if you still can't find it go ahead and cut some holes in the ceiling you're doing drywall anyway ! Happy hunting!