Is this problem a recent development? Do all the rest of the lights in the camper work properly? Are these two separate light fixtures, or one fixture with two lights? How are they turned on? Is it a wall switch for both, or a switch on each fixture? Has any other work recently been performed in the area of these lights?
It sounds like the wires for these lights may be shorted. Are the light housings metal? You might remove them and physically check the wires to see if they have rubbed against the metal edge and cut through the insulation. Another thing you can do is use a multimeter to check for voltage between the light housing and ground. With the light turned off, place the red lead of a DC voltmeter in contact with the housing, place the black lead in contact with a ground, If you read voltage, you've got a hot wire in contact with that light housing.
