This one is up there with "Star Wars Holiday Special" only not that bad. I remember watching this as a kid and being bored and amused at the same time. I think Gary Coleman was attempting to actually do "drama" in this ill-written attempt to enlighten the world about arson and it just didn't work.
Basically, you have Coleman's character who is having trouble in school, friends and family (obviously) and the more stress he comes under, the more fires he sets to public property. No, he doesn't turn to drugs or alcohol or teen suicide... he's got a disease that causes him to set fires! How dramatic! His parents seems incredibly stupid, not realizing that he's mentally anguished and no one suspects Coleman as the arsonist until he gets spotted, blah, blah, blah. It's pretty obvious how the plotline goes as well as the ending.
Probably one of the funniest parts is Coleman's "evil" expression during one of the blazes, his eyes lit up from the flames in front of him with this "burn you bastard, burn!" expression. Can you imagine Arnold as evil? Yeah, I laughed my ass off, too.
If you ever see this on TV again, which you probably won't, watch it if you want to kill two hours of your life. It's incredibly bad, stupid and absurdly funny at the same time.