The Secret Triwizard Challenge

It's sort of a stupid idea, but that spider probably can't hear well. If you douse your light, it won't know where you are.
"Nox," you say, and your wandlight goes out.
You definitely hear movement somewhere. The spider may not be able to see you, but you can't see the spider either. This probably isn't a good idea. Do you want to make another choice?