@edmaul69 Thanks for the information. I wasn't aware that aluminum was that good of a conductor. The heat sink is like most available for the Pi. Just with a glue that sits on the CPU. It could be weeks or months before I notice it's damaged. Thankfully, the Pi 3 isn't expensive (I have two) so replacing it won't be a problem. It's just that I hate having to deal with damage to an otherwise perfectly good Pi.
For my other Pi 3, the entire case is aluminum. I suppose the case itself acts as ground. Knowing me, I'm even going to be careful with that.
I guess I'm paranoid about the whole matter from experiences I had back in the mid 90's. It's just that moment when you feel the discharge and the words "Oh s**t." just comes out by instinct. lol...
I'll update this if/when I start to notice anything indicating hardware damage.