For renting check this out:

http://www.bwg-rhenania.ch/

I rented from them for a couple of years and was really happy.

For short term stays you can also consider a Gasthof:

https://gasthof-frohsinn.ch/

Was there for the first 3 months when I came to CH again.

Or:

https://www.sublet.com/city_rentals/...en_rentals.asp