Yes, the Decora-style Sliders are for dimming the 110v Rope Lights, forward and aft respectively. The switch in your shower (except for or course the digital temp controlled shower valves) was a special customer request and not normal. I take it you have tried it but see nothing happen? I would have guessed either the shower wall roller shade or the shower light lol. You would need to find (if it is in the coach) the original build order. The customer special request will be listed in the options/notes section.