Gloria-
No offense to my comrades in the fire service, but "electrical in origin" was once touted as an easy catch-all cause & origin determination for lazy fire investigators... I don't think that the real stats (properly investigated) would hold them up as high.
As far as what to do if you see a dangerous condition? Notify the H.O. in writing of a condition that needs attention. If he ignores it, it'll land on him instead of you should he try to pin it on you if the S hits the F.
A call to the AHJ is always an option, but usually the H.O. can figure out who did it, which could result in him bad-rapping you to his friends... despite the fact that you might have saved his house, or his life.