Is it at the firewall, which separates the engine compartment from the cabin, or on the inner side of the right side front fender?
If it's on the inner side of the right side front fender, it's could be the automatic transmission control "dropping resistor". It would have a four-terminal square connector. There's actually two resistors inside the part, and if either fails it would probably be noticed in the way the transmission works, and possibly cause a warning light (perhaps the AT Oil Temp) on the instrument panel to come on or flash.
I seem to recall posts here that indicated the resistor does tend to run warm.