Guessing electrical

I've developed a strange rattle when the engine is running and have found the source, but no clue what it is.
(2000 MT) ""Inside"" the right fender, there is a box, held on by 2 screws in the engine bay next to battery, there seems to be wires going to the bottom of it, and whatever is in it is causing a plastic rattle or a relay popping.
I'll have to remove the plastic inside the wheel well to get to it, but I'd like to know what this box is.
Anyone come across this before ?

You guys tend to have different stuff on your Canadianr rigs. Have a pic?

You could be right, just got word that the Daylight Running Light Module is in the same place for the Pathfinder. You wouldn't see much in a pic except for the 2 screws until I get the inner fender removed.