No marks, no apparent power source, no apparent comms package, very home made and hand labelled. Does appear to be open to the elements at one point; the red thing reminds me of some gaseous capture/exchange gear I have seen in the past
Usual suspects are traffic monitoring
But again between the size, lack of apparent electronics (you can power such things with a battery but no sense if there is available power elsewhere), location (nothing to be gained from suspending them in the ceiling like that) that one is out.
The open bit and what might be paper inside makes me wonder if it is a chemical trap of some form. It could be bacteria harvesting but I doubt a school would allow that for their normal students these days (not that I know upstate New York regs but most things I see tend to not allow such fun), and a swab would do better anyway. Faecal coliform and potentially airborne stuff might be an option here but it would be an odd one. Is this in the science block/area? If so it might be something of a teacher organised experiment as they are lest bound by regs as far as sample collecting goes, or they might be doing their own thing.
Smoke detection like that is one thing, though most such things in a modern school would be wired into something. Electronic cigarette exhalations would be tricky to measure with such a device (
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4565991/ covers composition) and the sorts of gear most schools play with and techniques they teach kids. Equally while you can lean on kids with evidence that would never stand up in court and they will often break I don't see it as especially useful for some kind of forensics, not to mention a nice smoke alarm a like with some official looking stuff on would do far better.
Could be ozone, sulphur or chlorine levels if someone used different styles of bleach.
