Your not an electrician with comments like that, at least i hope your not.
Your grounding system in your home has two purposes, one is to allow the clearing of faults quickly ( for example a direct short, allowing the breaker to reach it's threshold, which is higher than it's rating, quickly) and keeping the potential on all the metal components in the house the same, so if you have leakage to your ground system that is not enough to Clear ( IE. you can pull 25 amps on a 20 amp breaker for hours and it not trip), that the voltage is the same everywhere, ie. 40v on the fridge, means 40v on stove, so if you put one hand on one and one on the other, the potential is 0, 40v - 40v, you can't pass anything. Having voltage on this system, which is what he has on the Aluminum plate that he has his LED's mounted too, is not desirable. This is NOT a voltage nor a current carrying component, IT IS A MOUNT. If his LED are passing voltage through the screws he used, this is not normal for quality products, then he needs to compensate for this and use a different mounting, or plastic screws. Since having voltage on the mounting, leads to having voltage on his ground system if he grounds it, and having voltage present everywhere in his home. Which is not desirable in any situation. My fixture doesn't have voltage to ground on it. The one I bought from the store doesn't have voltage to ground from it's case....
For that matter, since he has voltage on his fixture, if he doesn't figure out where it is coming from, when he does ground everything and that voltage (which has to have come from a LED Driver) can get back to the driver, since right now he does not have anything grounded. So the voltage that is on his fixture is trying to find it's way home. When he puts his tester on his saw, he completes the path back to the driver (ground on saw, to neutral at panel, neutral to driver) electricity will take any path available, there is a possibility he will kill his drivers prematurely
I am a Master Electrician with 13 yrs experience in Electrical Work from small houses to a Geo Thermal Power Production Facility. I hold Current Journeyman License Cards in Oregon and Washington, will hold again my Idaho and have had both California and North Dakota Licenses. I stand behind any of my comments, feel free to come on over. We can get out one of my countless books on the subject and discuss if my comment that there should not be voltage present on the plate any LED is mounted too is incorrect or not.
It is never desirable to have voltage on the metal parts of any apparatus, period. This is what kills people and pets every year. It only takes
.08 milliamps across the right part of your body to kill you.
Now that we have dealt with someone who's IQ is to low or they were to HIGH to be commenting on this post, but I forgot, this is the internet. People can see through the web to know who you are and what you do off of one comment that they didn't fully understand. Which is always the problem with offering help online, people not fully understanding what is going on before typing their answer.
I do lots of experimenting on cheap chinese components, many will have to be replaced with more industrial style American style to hold up for any amount of time just too cheap, usually fake knock offs and some are of good quality, my system is all 12v, arduino controlled.
My custom built desk, found it needs to be a bit bigger for projects, oscilloscope, soldering Iron and tester take up to much room. My glass mouse pad is recessed into the top.