Touch plate system is the the oldest low voltage switching there is. They are a 12 vac system and you can use a 12 v continuous duty relay and standard light switch to replace them. The original "lite touch" system was a two wire system as where newer lower low voltage systems were a three wire system with latching relays, GE RR7. I have repaired them with the 12 volt relays from Grainger---it works.
