Why does my Mac glitch when touching any metal?

My Mac was like touching another Mac, and the tab my trackpad was hovering over started glitching. I couldn't control the trackpad very well either. I had placed my phone on my computer keyboard before, and the same thing happened. Once, I had a metal water bottle touching my computer, and I couldn't click Enter in the calculator, which was on the side of the screen that was touching the computer.

[Re-Titled by Moderator]