From what I can tell, you’re right that it is bolted/nailed to the stud.

This is only a temp change, as I’m looking to get up into the ceiling to look for excess water, from a sink overflowing.

The smoke detector drank a bit of water, so I’ll be buying a new one today.

Honestly that box fan filter seems like a bigger and cheaper HEPA filter, which I like. Definitely will look into the air monitor as I wanted a humidity monitor already.

I was honestly planning on getting a test until I learned about the monitors. Might just do both

Can I get away with just keeping a CO2 detector in the kitchen and bedrooms, or should there be one in the basement as well?