Ideally the thermostat should be mounted to a rafter along the wiring path and away from the draft of the fan.
Install attic fan thermostat switch.
Leave enough cable at each end to work with.
Remove the cover of the thermostat to expose the black and white wires as well as the green ground screw.
Place it so it s facing in the direction of the air that s being drawn out of the attic by the fan.
Make one of your wires from the 12 2 either red or black a direct power to your thermostat.
Run a 12 3 w ground from switch box to fan thermostat box.
Use the hammer and staples to secure the cable to the joists at 12 inch intervals.
Run nm cable from the attic fan thermostat to the attic light.
Step 1 secure the switch.
Screw this box to the plywood so it s in the direct path of the airflow step 11.
Start by screwing the thermostat switch to the plywood frame that houses the fan.