I would look into wireless battery powered switches / buttons using what’s called “Matter over Thread”.
See here for why:
Here is a button I found:
Note that I don’t know yet how reliable all that is, but its definitively the first avenue that I recommend to look into.
You could make it all work together using Node-RED.
And be aware that you need one additonal hardware product that is a so called “thread border router”. I did a quick search, and this one looks nice. Just needs power, conveniently provided from USB-A instead of typical AC plug, so its easy to install in a DC oriented install like a camper van:
