Except in a fireplace. Last summer we had a carelessly bundled wire shake loose and hit the hot exhaust riser and cause a dead short. It was amazing how fast it burned through the boat. We were lucky. I've been paying particular attention as I've installed some new wiring onboard to reduce that potential. In going through things, I've found one battery cable that looked fine had actually had a little chafe from the edge of the engines heat exchanger. That's safely corrected. It's a good time to take a quick look at the potential for an electrical fire onboard.
Just a few years ago, two men on this new lobsterboat noticed smoke coming from the engine compartment. When they opened it, flames engulfed the boat. They only had time to jump overboard! Suddenly, their fire, was our fire in the harbor as wind pushed the burning hulk into the inner harbor.
My boat is just upwind of the burning hulk. Most of us were lucky but a few boats suffered damage.