Serious question: if you care about your privacy how can you stay in an Airbnb with little way of thoroughly checking whether the owner has put a camera in the bedroom, bathroom, etc?
A little faith in humanity and in your ability to judge character. If you’re absolutely paranoid about this sort of thing, how do you even use a public restroom? How do you know your own house doesn’t have cameras watching you? Even James Bond lets his guard down now and then.
Install Fing which is an iOS app that scans the network, and look for cameras, but it is not so useful anymore since Apple removed the possibility for apps to read mac-addresses.