Another possible reason for two switches is the old... Some other use.
For example.. A "Door Ajar" light on the dash.. Thogh that is not something I have ever seen on an RV, I see not reason not to have one (I also have not looked for on).
On a reverse note: I took a common Automotive Door switch (The plunger type) specifically mine is a JEEP part number.. Mounted it on a bracket over the top extendable step so when the step is FULLY RETRACTED the plunger is plunged.. turning off a warning light on ye old dash.
Home is where I park it!