This is how i installed my gable end attic fan. I bought it from Lowe’s/Home Depot on sale and put it in my attic to try and cool it down in the summer, because our upstairs was getting too hot. It was cheaper than running my AC constantly. Also i wired in an override on/off switch and a pilot override switch to control the thermostat on the fan.
(Disclosure Note: Please note that the Amazon link(s) above are affiliate links, and at no additional cost to you, I will earn a commission if you decide to make a purchase after clicking through the link.)