oil lamp or flashlight :shrug: that's how I do it.
Or you can rig up a cheap solar light and just ensure the panel is facing the best sunlight available, IME the solar light gives around twenty minutes good light after recharging but will glow dimly all night.
Off-grid options, 'cos that's all I have here. I believe there are solar or 12v work lights to be had that should be quite bright, haven't seen any in a budget of almost nothing, yet.