Well, my home did burn down last year, so I am probably as paranoid as anyone about it. (Although it had nothing to do with growing or lights, just an old house, and it had ancient wiring.) The steps I have taken to minimize the chances of me once again standing outside half-naked in the cold watching my home burn down:

1) I have a fire alarm in every room, and I change the batteries regularly
2) I have fire extinguishers on every floor
3) I don't keep any outlets or plugs within 2 feet of the floor
4) I don't use anything near the lights that is particularly flammable
5) 95 percent of the time someone is home to keep an eye out
6) The house's entire electrical system is brand new, top to bottom

It really is an important issue, although I'm not going to harp on and on about it. All I know is, I am quite willing to take a fair amount of precautions in order to minimize the chances of ever repeating that house-burning-down experience. If you're wise, you'll do the same. If you're not wise, and you're unlucky, and your house burns down, then you'll be wiser the next time, I'm sure of that.