I had some fun with this at a local chain store selling computers. I could feel the same thing in a couple laptops on display. When one of the "geeks" came by to help me, I showed him what I was doing and asked him if he could feel the electricity, too. He did. Then I said "I think you have an electrical short in your power somewhere and something's not grounded right ... and if you unplug the power this will be safe again." (I specifically used those words to imply this is scary stuff). He unplugged it and behold, the problem went away. He plugged in back in and it was back. Not all the computers did that and I explained that the plastic ones were safe when something's wrong with the power. He got the manager and showed him, and the manager shut all the computer displays down. I managed to hold off laughing until I returned to my car. I haven't been back there since.
Ha Ha, funny, NOT!
I wonder how much money they lost until it was discovered they didn't have an issue.......
Funny thing about those power supplies, some of the major name brands still have 2-wire cords and charge $90-$120 for them, but if you buy a cheap Chinese knock-off power supply, many of them come with 3-wire cords.
I replaced a faulty one recently, the OEM guys wanted $95, I got one shipped to my door for less than $15 and it showed up in 3 days. I'm seeing the same thing going on at work too with different brand names.
