Anyone know if there is a secure storage company for Motorhomes in cantons Valais, Vaud or Schwyz?
I am thinking to buy one but have nowhere to park it

Maybe enquire at a local 'campsite' (the typical Swiss type - with glorified garden sheds and static caravans, with just a small piece of grass for camping).

Largish ones, that I remember seeing, seem to have a few camper vans in the parking area, which are obviously lagered (stored/left) there.

You could try tutti.ch (an on line marketplace) :
http://www.tutti.ch/ganze-schweiz/im...te?q=wohnmobil

Many farmers will look after motorhomes for a fee. Ask at large farms with old barns. But the advertising might not appear until the Autumn....

Indeed you could Google map the train from Arth-Goldau to Zug and see where it meets the highway. Where the highway is raised, many landowners are offering this service.

Secure by being in Switzerland...!