I've just installed two Rio Grande Pitbulls in my Steinberger, and I'm getting a little bit of hum. They are 4 conductor pups, and I've wired them with nothing but a 3 way switch between them and the output jack. I believe I have everything wired correctly, but I am still getting a little hum, which appears to be a ground issue. It's not a bad hum (like a broken ground would be), but it's annoying. When I touch the ring for the switch, the noise goes away - problem is that there's no route for a ground wire to run to the bridge, where you usually make contact for the ground to run through you. What can I do to make this noise go away? Do I have to route a ground wire to the bridge, or is there a simpler way?