Fire detectors work with batteries and make an audible sound when the batteries run out.
The camera thing is strange. If you use a hidden camera, it shouldn't flash red or otherwise draw attention to itself when the batteries run down. Somehow the meaning of hidden gets lost then.
What might also be worth considering is that the was accessed via wireless to connect to a receiving station. In EP5 I think Leon had said so Derek would have to press a certain flashing button on the drone for the MC's cell phone to connect to the drone.
That in turn would mean so that the camera was not installed until the party, because otherwise the connection would have already existed. Who was that coming from the direction of the Moose Lounge when Quinn and Vinny ran into each other at the aquarium? Lily.
Lily is there with her friends. Rose has a great costume on. A sexy police costume. But why would Lily put on a camera? That doesn't mean she's an undercover cop, but she's spying on something or someone, and probably for the madame. This in turn generates a question? What is the real name of the Madame?
If I were to guess, I would guess Helen, the mother of Maya and Derek. Why? Josy said so all three of them have a mother situation that Maya now has a chance to say it. Maya mentioned again so she trusts the MC but was very uncomfortable talking about her mother. We only learn so she loves her mother and that her name is Helen. But the ghost (ninja) says in the argument with Derek so he would fuck his mother. Well, if Maya's mother is the Madame, the Madame would also be Derek's mother and the Madame fucks for money.
Maya is afraid to lose the MC if he would find out that her mother is working as a prostitute and stripper. That's why Maya trusts the MC in EP7 so he won't fuck her mother and in EP9 she trusts the MC so he won't run away like a snowflake again when he finds out what Maya's real mother does for a living.
The reason the Madame has the MC watching her is simple. Maya is a delicate little plant and Helen wants to go out of her way to make sure her daughter doesn't get a horny dog.