You paint glow-in-the-dark specks over the walls, ceiling, and floor of a room in your house to look like Constantine's void rooms (in The Sword and in Strange Bedfellows) - I have actually done this, and it does loook really cool. It is important, however, that you get paint that glows white, and not yellow or green. The white glow-in-the-dark paint is more expensive, but well worth it.
#1345 by Black