Free Range Learning
My mother, a registered nurse, had treated kids suffering from burns. Because she was afraid her own kids might play with matches, she told us we could learn to light them any time. All we had to do was ask.
Her method was to fill the sink with water and let a child stand at the sink, while she stood right there. The child could strike matches and drop them in the sink whenever the flame got too close to his/her fingers. A moment of singeing is likely to happen once or twice, which is far more instructional than any adult warning kids about fire. Each one of us did this a few times when we were small, and then our curiosity was sated.
I did the same thing with my kids. They usually got interested around the age of four, asked to do it a few times, and then were done. They were cautious, informed, and far safer around flames than other kids their ages.