i just got this P Bass as payment for building a website, it needs some work. it didnt have a jack when i got it, i put one in last night and it works, but theres a pretty loud hum whenever i touch the bridge. i havent put strings on it yet, but i can only imagine that it will hum when i touch the strings too. the ground wire is mounted under the bridge and is making a good connection, should i try grounding it somewhere else? any help would be much appreciated.. thanks.