For what little it’s worth… consent is not needed if there’s no expectation of privacy… if your visiting somebody else’s house… Bathrooms- yes, bedrooms (where you’re sleeping,) yes…
But a hidden camera in, say, the hallway outside, is perfectly legal. Now if the person is a resident (or, like Airbnb,) they have much higher expectations of privacy.
Also… I would suggest that cameras inside residences generally serve no real purpose at all- and are almost universally employed by creeps. (Exception being apartment entryways… if peephole cameras on the apartment door are not allowed.)