I have a light/fan combo in a bathroom that are controlled with a single switch. I want to control them separately, but running a new wire would require ripping out drywall, which I don't want to do. It is in a guest room, so it can't be controlled with an app, even though I know there are ways to give guest access to certain home automation systems.

The power runs up from the floor, through the switch, and then up to the fan, so I have power at both locations. The wiring for the fan is in the attic, so putting something up there is easy.

What I imagine exists is a remote double relay that can be controlled by 2 physical switches(preferably single gang, but I am prepared to open up the wall a bit to install a double gang box). I would prefer that the relay be powered by 120v, rather than a 12v device that needs a plug somewhere, but its not a total deal breaker.

Anyone have any ideas?

So I've been out of the loop on camping and, more generally, outdoorsy stuff beyond day hikes for a good couple of years now. In my absence, it seems like a large chunk of the manufacturers I used to rely on for flashlights and headlamps (Black Diamond, Petzl, Fenix, etc.) have switched over to lithium batteries, many to USB chargeable internal batteries.

That feels weird to me, coming from the era of "carry a couple of spare double and triple A's with you", since you only needed a few of one or the other to keep all your lights going, even on a longer trip. Given that everyone's doing it now, though, I'm assuming it works out fine.

Anyone have recs on what brands are good these days, what models, and how to buy to maximize the "keep all your lights going with the least backup energy sources" factor?