Should be able to, yes. But first, do you have a multimeter? And do you know how to use it? It would be nice to verify that it's 110 VAC before you connect something to it. But be careful measuring the voltage across the black and white wires! You don't want to touch the bare wires, or have the black wire touch any metal in the trailer, including the ground connection in the box (where the bare wire and green screw are located).
A 110 VAC fixture would connect white to white, black to black, and the bare wire on the fixture connects to the ground connection in the box.