Kirk because there is power to an existing light fixture in the attic area then the additional light switch and light fixture will be relatively straight forward.
Put switch in attic.
As with any electrical project where new devices and wiring is to be installed you.
Connect the copper wires together.
Installing a j box in the attic is easiest if the attic is unfinished and used for nothing more than storage.
The other thing is unless you are installing a massive unmanaged switch a cheap 5 8 port switch is only a few bucks.
If you will need to fish wiring through a wall drill a hole through the wood plate in the attic only.
Attics often have electrical cabling running through them so an electrician or experienced diyer can easily tap into an existing circuit.
This might keep it running.
When cutting through drywall from the interior of a room use a utility knife and cut carefully you don t want to drill through a hidden wire or the paper.
You could take a metal cased switch and add vent holes and a fan.
And use semi rigid wiring fish tape to pull your wiring down to your outlet location.
A few solutions come to mind.
60 or 1 5m from the floor is common.
Connect the black and white fan wires to the black and white switch wires.
At the switch connect the white wires together.
The light switch should be located close to the opening to the attic entrance where a 2 wire cable with ground is installed up to the existing light fixture.
Typically even with good ventilation you are going to hit 25 30f above ambient temp so if you get temps up around 100f sometimes it ll be more like 125 30f in the attic and easily add 10 15f if the attic is not well ventilated.
Install a hard wired light fixture.
It is perfectly safe to install a switch in the attic.
Add a ceiling vent and insulate above it so the switch is in the cooler room air.
If you have central ac ducts in the attic you can install the switch in the duct to keep it cool.
What i was commenting on was the extension cord in the attic.
Wherever that extension cord is connected to power you could extend that circuit from there to the poe and then connect the poe.
Decide where you want to place your switch.
Attach the ground wire to the ground screw on the switch.
Attach the black wire to the top brass screw on the switch.
Place the light switch near the entry for convenience and use a switch with a warning light that reminds you when the light is on.
Go around your house and measure the height of other switches.
Attic light and switch wiring.