My attic fan died on the hottest day and I found out why in 20 minutes

Last Tuesday it hit 98 degrees here in Dallas and my attic fan just quit around 2pm. I went up there thinking it was the motor but turns out a cheap plastic junction box had melted and the wires were just hanging there touching bare wood. Scared the hell out of me because that's how houses burn down. I killed the breaker, swapped the box for a metal one, and re-stripped all the connections in about 20 minutes. The old box cost like $2 and the metal one was $6, so this was a five dollar mistake waiting to happen. Go check your attic wiring if your fan is more than 10 years old, especially if it's plastic. Has anyone else found melted boxes up there or am I the only one who got lucky?