Galvanic reaction starting a fire?

I thought I'd get some input from some other minds in regards to a situation I encountered tonight.

We had a smoke investigation tonight at a mobile home that had been added onto. There was smoke coming from the crawl space. When we got into the area we found some particle board, dimensional lumber, and paper insulation backing smoldering.

I searched and searched for an ignition point. No wiring, no smoke products, no burning near the area- nothing.

While looking, I noticed a copper water pipe that had a leak in it. The leak happened to be right were galvanized wire was holding it off the ground from the frame of the trailer. Where the frame where it hung came out to the outside of the trailer is where the smoldering was.

I'm not overly familiar with galvanic reactions and electrolysis to the degree of knowing how much heat it can generate, so I'm wondering if it's enough heat to start materials to smoldering?

The only other explanation I can think of is if a wire was hitting the trailer frame and shorting against a screw or nail in that area, but I couldn't find any indications of such.

I would go with number two or other

Any lightning in the area??

Floating neutral???


Energized neutral??

I'm wondering more and more about the electrical aspect. I can't imagine a metal-to-metal reaction creating sufficient heat.

After talking with one of my guys that was inside, there may be more electrical problems that I wasn't aware of until this morning. Apparently with the power shut off to the pole there was still some current running through the system- enough to make the light bulbs glow slightly.

The copper vs. galvanized may have been a coincidence, or maybe even accelerated by the current floating through everything.

Gotta love heavily modified mobile homes...