Of course, you can also rent a roadsurfer camper as a Swiss citizen. However, there are a few things you have to keep in mind: If you rent a vehicle from another EU country, you must declare it at a border customs office the first time you enter Switzerland! You can find the opening hours of the offices here: BAZG
When entering Switzerland, you must request a customs voucher "Vormerkschein" 15.25 for the vehicle at the Swiss customs office. You can get this at all manned border crossings during opening hours in tourist traffic. With the customs voucher 15.25, you have 8 days (calculated from the start of the rental contract) to re-export the vehicle. If you enter Switzerland more than five days after the start of the rental agreement, the customs office will issue you with a 15.25 provisional "Vormerkschein" for three days. You must be able to present the rental agreement at any time.