Should be placed a minimum of 1,5 meters away from the working area, but you can hang practically as many as you like around your darkroom if you want to increase visibility. Glue it to the wall with three dots of hot glue, or hang it from a hook and chain.
Tip: If you find yourself standing there with a dead lightbulb, and you've forgotten to order a replacement, you can steal the lightbulb from your refrigerator as an emergeny substitute.