Sorry, I'm going to bow out of this one. There are two poles on the switch (or more) and two poles on the battery plug. Don't know if any other wires on on the switch or on the plug and I don't know what the two wires are for on the servo controller other than possible power leads. Looks like it may be a phono plug, if so, the outside connection is the negative and the tip is the positive, provided the battery is wired that way. Without a schematic I can't make a recommendation. Just don't want to have you hook up power to the wrong place and blow it up. Best if you can have someone look at the actual product. I could tell you how I THINK it should be wired but again without seeing it I don't want to try. If this is a manufactured unit contact the people that made it. If it a home-made unit, someone has a schematic. Check around for someone that has a little electronics knowledge to look at it. OK, here's my best guess for information only, I believe the red (+) wire will be connected to the switch and the black (-) wire will go the the negative (outside pole) on the plug, you also need a wire from the positive pole on the plug to the other side of the switch, but if you smoke it don't hold me responsible.

Good luck
Marv