Connecting kill switch on a 3.5hp Briggs?

On my Briggs and Stratton 3.5hp in a go kart I have two wires attached to a plug which is plugged into the ignition/magneto embly. One of these wires has a connector on the end, and one of them is stripped to the copper. Do I just connect the one with the connector to a switch and then the ground on the frame? And leave the other one hanging? I ume it has two wires for a reason... But I'm not sure why.