I do the same as SAH above. I found this absolutely necessary on PECO switches- using the contact of the switch rails to the mains proved to be too unreliable even in a clean room. I binned 6 PECO switches trying to make them reliable... So, I now hot wire them and use a couple of insulators on the frog rails. Now always reliable. I do the same thing on Atlas switches even though I never had an issue with HO or N scale since the late 1970s. Kind of a belt-and-braces thing, I guess...