Horror movie tradition dictates that you must use a cruddy alkaline powered light with bad electrical contacts and a fragile incandescent filament. If you can’t find one of those a nearly empty lighter or a candle is acceptable.
Fun fact: I play one of my games with a mod that adds a flashlight. You get the options of incandescent (kinda dim, wide spot with no spill, warm), halogen (less warm, longer reach, floody) and LED (perfect daylight-like tint thrower with a tight spot and wide bright spill, like a BLF GT Mini). Guess which I use to keep the atmosphere