This unit is an old Honeywell thermostat. Wait for it….
Waaaait for it
The fan contactor:
Breaker panel. These Pushmatic breakers are known for being a little flaky. It’s all decommissioned.
Why black and green? The National Electrical Code says green is ground. Nothing else. Ground. I dunno. This is outside of my pay grade. 😉
Nooooooooooooooooooooope! That’s the worst possible error!!