I know how weird and improbable this sounds, but this is what’s happening to me.
Roughly 10 days ago I increased commit_interval in Recorder settings from 2 to 10 to further optimize writes.
The same night, three different lights randomly turned on. One is wifi, one is BT Mesh and one is Zigbee, so no one faulty integration. This kept happening for the entire week until I realized I made this one change. I don’t think there was any other update.
One of the lights (a BT Mesh light) also kept turning on on EVERY HA restart. This and one other light of the three are not driven by any automation or motion sensor.
I set commit_interval to 2 again, restarted… and the lights never turned randomly on again, and the BT Mesh light does not turn on after restarts as well.
I have been using HA since 2018, I’m no spring chicken. I know how to check automations and what triggers what. I have no explanation for this though.
Writing this here for posterity in case someone else has similar issue.