The Chalet model name is given to motor homes they manufacture for rental companies. They may have features that are not standard. You should call Winnebago and give them the serial number of your mh. Is your unit a class C or A? I've seen both with the Chalet label.
Thanks for all the help, I called Winnebago - turns out this model is the same as an Outlook. The mystery switch is for an outdoor cleaning station which this model does not have so it does nothing. Also found out these is a recall on it.