We had the receptacle above the kitchen table start fire one day.  I disconnected the shore power and removed the plug receptacle.  The first photo shows how bad the receptacle had burned.  The second photo shows the inside of the receptacle.  I think the reason it shorted out was because of the type of connectors and the tension on the wires.  I didn't like the type of receptacle that had been installed and went to our local Home Depot to purchase a better type that would be a more secure installation.  I had to make a small box out of 1/2 inch birch plywood.  The new receptacle now has a breaker built in which the old one didn't have.  You have to make sure you install the line wires on the line terminals and the load wires on the load terminals.  I used a Radio Shack Volt/Ohm Meter (VOM) to find the live wire versus the load wires.

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