Swiss law allows temporary sublets if you cannot use your rental property due to unforeseen circumstances. Hosts that are tenants need to get permission from the landlord each time they want to sublet their accommodation, and the landlord is free to refuse to consent. If the landlord agrees, you may need to decide on the conditions of rental, i.e., how often it will be rented, the price, specific requirements, and which rules the subtenants need to follow. Most importantly, you are only permitted to make a profit of 20% on the rent you pay.
Although written consent is not a requirement but will be helpful in the case of a dispute.
You can rent out your home as much as you like if you are the landlord as long as your canton and condominium association permits. The rent charged in this case must be similar to the average monthly rent which could be charged for the same property.
Also, the Federal Act on Foreigners and Integration (Foreigners and Integration Act, AIG) (s16) states that commercial accommodation provides the details of each guest to cantonal authorities. Therefore, in many cases, you need to register your guest with your cantonal authorities or local police. Other rules depend on your canton, so do well to check for other laws and regulations that concern tourist accommodation rental in your canton.