There are several ways for the light to illuminate the darkness. You can flip the switch to turn on the light bulb. You can use a flashlight. You can light a candle. You can even light a torch. However, not much people have much need for torch lighting unless you're going down some dark obscure tunnel from a bygone era. Most people illuminate the darkness with light with either a light bulb, a flashlight or a candle. Make sure the candle is extinguished before going to bed so you won't run the risk of burning the house down by accident. I doubt the Gentle Reader would be so accident prone though. And that is very fortunate.
And as I'm lost in thought about light bulbs, here are some photos of Karen Gillan.