I've seen my brother splice in new wires by squishing two ends together and covering it with some heat-shrink tubing.

I'm a big handyperson, but I draw the line at electricity. I bet it's easy enough to do this, but I've never been taught. There must be some DIY sites on the web? It's just that the potential cost of a mistake bothers me.

Yes, you can just lengthen them, if we're talking about a matter of inches or so. You should be able to get wire twist connectors like these at your hardware store. You strip the ends of the wire, twist them together a little bit before the bare ends, and twist the cap on. Make sure you get connectors for the correct gauge of wire that you're using.

Oh, they're also called "wire nuts", according to Wikipedia. You can see them in use here.

Oh yes, wire nuts are infinitely better than heat shrink tubing.

Thanks so much people! Sounds doable then. I've used wire nuts lots of times (you need them to install a light fixture) and I just need a few more inches of wire to resolve this problem.

I do like to avoid paying for professional labour as often as I can. It's hard enough scraping together enough money to renovate my entire house.

Wire nuts are a good idea (they're sized according to the gauge of the wire you'll be joining, so be sure to get the right size). One downside to the sperose's-bro approach is that the wires might pull apart later.

Make sure that the pieces of wire you're attaching are the same gauge as the ones that are already there (a little bit thicker wouldn't be the end of the world)--if they're thinner, there's a chance they won't be able to handle as much amperage as the existing wires.

Oh, and be sure to switch things off at the fuse box before you start working. You already know that, though.

And try not to worry too much--I've been shocked by 110v a few times, and I'm still here, dispensing electrical advice on the internet.

I just got here in time to find everyone already said what I was going to say.

The breaker if off, while you are doing this, is it not?

(you may be able to just pull more wire out of the conduit, if there IS conduit.)

I've pulled on these wires. They won't come out any further than they are.