In a moment of weakness, I bought a D-Link wireless (wifi) water detector for the sump pit (it was on clearance for $30); it relied on a D-Link Home cloud service (free) that was closed down a few years ago.
Not wanting to toss it, I repurposed a spare Chromebook 14 that I was going to recycle and turned it into a Alpine monitor for the water detector, which I'm powering from the Chromebook's USB port (if power is lost in a rainstorm, I need to know about it before the sump pit fills up).
An immediate issue was that the D-Link firmware tried to "phone home" every 24 hours and would drop from the local network, since the server was kaput, and I had no clue what response it was expecting from the server to keep it alive. Solution; "reboot" the unit by interrupting USB power (with a Pico and MOSFET) every 23 hours. There's no question that home automation should work without the internet.