I'll also add one more warning to this. I told this to a friend of mine some time ago and he laughed and said it wasn't a problem. He did blow the circuit's fuse when he tapped another load into it. He said he fixed the problem simply by changing the fuse to a larger value.
Don't ever do that, the fuse is there to protect the wiring first and foremost. Every gauge wire has a maximum
ampacity. You can look that up in an
ampacity chart. If you exceed it, you run the risk of damaging the wire and causing a very expensive problem. Fuses must never be changed to a larger value.