Hi Pedro,
I took delivery of my ES mid January and it had a earth hole drilled from the bridge post closest to the bottom F hole. If you get a long 3mm drill there shouldn't be much wood to drill through to get to the hollow area if you don't have a hole drilled. Have a close look you should have an earthing wire hole near the bottom bridge post hole
when I knocked in the bridge post piece I ran a long earth wire through to the F-hole for soldering to the back of the pots after
good luck but the tubing idea of Gav's is gold and should be patented !
I'll try and follow your forum and answer any other questions you have
cheers Wokka
