My mate has the old round pop out timer switches in a 3 story house and wants to replace them with normal switches but the switch wire is'nt marked, how do you know which one is the switch wire also do you use two way switching on all 3 floors? i.e. there's a swithch on the ground floor, 1 on the first floor and 1 on the second floor hallways. When you press 1 swith all 3 lights come on for about 2 minutes. What's the best way to replace the old swithes as the wirning is old and does not have a strapper cable connecting each switch.