i alwaysseem to stumble appon something i dont know too much about guitars and this is one of those things ive been wondering. what exactly is a ground wireand are they only on tremolo bridges.
If you're having troubles relating the article to a guitar, you should be looking at the #3 meaning.
MG Free At Last
If you've ever replaced a pickup or poked around the inside of a guitar, your pickups use ground wires. I've replaced a vintage p-90 style gibson burstbucker, and you peel back the shield, and use it as a ground.
The grounding reduces hum A LOT. And no, it's not only on trem-bridges, on hardtails the ground is under the bridge.