Got a bunch of RPIs, some of them retired.
One of the active ones runs a MediaWiki engine (if it detects my home wifi on startup, it acts as a mirror slave to the master installation on the server, if not, it opens a wifi with my home wifi’s credentials and offers the wiki as read-only).
Another one runs a DB that controls a number of ESP8266 clients controlling lights, motors, and sensors.
If you don’t care for the looks, just put it down where needed, and fix it to whatever is around with cable ties.
I did the same in my daughters shared accommodation. Officially they had wifi in all the student rooms, but my daughters room basically had no reception, so I ran a cable from the other end of the flat where the router was down the staircase into her room for a local AP. When she moved out, it was a quick job with a pair of pliers to get it out again.