I’ve seen wireless doorbells. You plug the chime part into an outlet and there’s a button, usually battery powered. You could use double-sided tape to affix the button to just about anything. Ring the doorbell to summon you. No vision needed, only one button.
Something like this. (Not endorsing this specific one, just to show what I mean.)
I have something in between. The wiring was shot on my old one so I bought a wireless "dumb" doorbell. It doesn't have a camera but it looks "smart" so I've not had any porch pirates in an area where thy are common.
I ordered this and tested it out in the woods and it was loud enough and the transmitter was far enough away to make it interesting. I never actually put it out, and completely forgot I had it, so thanks for the remind! My fear is that someone will simply walk off with the stuff way before the battery goes or rust takes over. I think I will put it in a location that requires a bit of a hike, and I will treat it like a trackable: once it is out, kiss it goodbye and hope some people get some fun out of it before it goes missing. I know, I'm jaded.
It's a wireless doorbell. The base unit would be plugged into an outlet somewhere. Not really a "smart" doorbell. They probably took the rest of the doorbell with them not thinking about it or it got thrown away.
Here's one on Amazon for $15.99 https://www.amazon.com/dp/B076X3HRRF
Hardwired doorbells are a bitch! Get a battery powered unit (the “bell” plugs in2 an outlet) like this...
Wireless Door Bell, AVANTEK Mini Waterpoof Doorbell Chime Operating at 1000 Feet with 52 Melodies, 5 Volume Levels & LED Flash https://www.amazon.com/dp/B076X3HRRF/ref=cm_sw_r_cp_api_i_5J8tCb4X59XCK
Personally, I'd remove them both and replace with wireless models. Sure, the buttons need batteries, but you have a lot of options with rings. I have this one for my home: https://www.amazon.com/gp/product/B076X3HRRF/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
And this one on a rental unit: https://www.amazon.com/gp/product/B074VPC554/ref=ppx\_yo\_dt\_b\_search\_asin\_title?ie=UTF8&psc=1