I think you could do it by using three ways so that the common is hot, one "traveller" srew goes to the bulb in front, the other srew goes to the bulb behind. then when you flip the switch it turns one off as it turns the next on. they would alternate having the one directly above on the sitch in front and behind. It could be done, it is a logic riddle. I'd need pencil and paper to really figure it out.
