nope, just grind enough material away on your switch to run the wires outside and go to town. If you are paranoid about water I would run a little dab of silicone sealer where the wires exit the swtich after it is installed on the bar, and go through the sleve and make sure there are no breaks for water to get in. If there are just wrap some electrical tape around it. If you wanna get fancy you can get convoluted wire wrap and enshroud the wires in that. Also don't forget to zip tie the wires to the bars so they don't hang down and look ugly. Two or three per side should do ya.