That reminds me - we're staying in an Airbnb later this summer and I've been meaning to research gadgets to detect hidden cameras. Now I guess I need to look out for microphones too. We're going in quite the dystopian direction.
Unless you get a nonlinear junction detector, I'm not sure any other device works as well. I remember seeing a news piece where they pay someone to plant a bunch of cameras, and the reporter tries a bunch of different devices and still misses some.