Have you stuck a volt-meter to your laptop to see if it is actually running a current through the body of the laptop? If it is, might be worth having the laptop serviced.
and It's actually a "feature" of macbooks in general, not this particular one.
I mentioned under another comment:
That A former coworker actually pointed it out to me.
"Ugghh, don't you hate it when you slide your finger across your laptop and it's giving you that buzz?"
I was like "What are you talking about? It's just the brushed aluminum feel?"
He told me to unplug the charger and try again. And Holy moly indeed the buzz stopped.