Has anyone come up with any ideas on putting a wireless light on a timer into a tractor type coop that doesn't have access easily available for a wired light bulb??
I assume this is for winter egg production? In which case, you may not necessarily need a timer. If you get one of those solar-powered driveway type lights, it will automatically run for some number of hrs after sunset and then shut off (because the charge poops out). Depending on your needs, this might be quite adequate, especially somewhere tiny like a tractor that doesn't need *much* light.
The subject of timers for battery-operated <whatevers> has come up a lot of times on BYC and I do not recall ever seeing anyone have a solution. Presumably it exists somewhere in the world, or could, but my suspicion is that it's quite hard to find and probably expensive. If you do turn up a timer for battery-operated things, though, you would have a LOT of people here wanting to hear about it
I used one of those driveway lights in my coop. I just had to take it apart and add some wire between the light and the solar panel. has worked great for last 5 years.