After a few weeks of playing with this and not being plunged into darkness I’m soft launching my latest #HomeAssistant helper.

Wasp in a Box is an automation pattern for enclosed spaces (bathrooms) where a door and motion sensor are used along with some timers to work out occupancy even if there's no constant motion.

Experimental release is available if you like living dangerously.
https://github.com/andrew-codechimp/HA-Wasp-In-A-Box