I guess I'm focusing more on the "lights are off" part, although that's just an aside. "Conscious" and "lights are on" seem like alternate ways of saying exactly the same thing.

Nagel's "is it like something to be" terminology has always struck me as wilfully contorted and confusing, but amounting to the same thing again -- you're conscious if you're conscious. It doesn't help us explain consciousness and it doesn't even help figure out what things are conscious and which aren't. Is a plant conscious, or a rock? Writers can certainly imagine what it might be like to be those things.