Why the Cause May Not Be Electrical
Ceiling fans, overhead light fixtures, and circuit wiring are common victims of misinterpretation, for a number of reasons:
1) Because fans and light fixtures are normally located near the ceiling, they can be exposed to more direct flames than other items in the room, so it's not uncommon to see them substantially burned by a fire. The more severe damage makes them prime suspects for many investigators.
2) Ceiling fans are usually installed through the protective layer of drywall which forms the ceiling. During installation, a hole is cut in the drywall, which compromises the ceiling's fire-barrier effectiveness.
If a fire occurs in the room below the fan, the flames and heat tend to "vent" through that opening in the drywall, and the fan, of course, becomes significantly burned as a result. A typical post-fire observation is a charred ceiling joist right where the ceiling fan (and the hole in the drywall) was, but to some that becomes evidence that the ceiling fan had "overheated".
3) Electrical wiring is
commonly found melted in moderate to severe fire scenes. The melting can occur for several
reasons - a] extreme temperature, b] electrical arcing, and c] alloying.
It's important to be able to
distinguish which of these conditions has caused the melting, and why that condition
existed at the fire scene.