Not fully sure on that one..
So the lights that must stay on are the lights on the ground level, if you flip the switch, they get shut down, and the monsters can come (scared of the light/want to avoid it so they stay on the roof?).
In the early panels you see a hole like shape on the roof, with seemingly natural light, and after that, it's gone, and you only see that hole, but bigger, in the last panel, so there's a connection there, the doors are also opened on the last panel.
The windows also have light in them, until the switch get flipped, so I assume that whatever things are behind the doors left due to that idiot, I don't fully get it, but guess I'm not figuring that one out.