Pete, I just typed Macbook Pro electric in Google and the first four auto completed suggestions are:
- Macbook Pro electric shock
- Macbook Pro electric shock while charging
- Macbook Pro electric vibration
- Macbook Pro electric shock vibration
Here's a screenshot:
I am sure we can agree Google auto completion suggestions are based on common search queries. To be sure, I am browsing in private mode, have cookies disabled for good measure, and am not signed in to any Google services - so that my search history can't bias the suggestions. You can read at https://support.google.com/websearch/answer/106230?hl=en that Google auto complete suggestions are mainly based on what other people have searched in the past.

Here are some of the top results, from what I am sure you will recognize as mostly popular websites.
- http://forums.macrumors.com/threads/macbook-pro-giving-me-electric-shock.1625275 /
- http://apple.stackexchange.com/questions/32417/how-can-i-avoid-my-macbook-pro-gi ving-me-minor-shocks
- http://upsticksandgo.com/getting-buzz-macbook-pro-electric-shock-travellers-tip/
- http://www.cnet.com/uk/news/ouch-my-mac-shocked-me/
- http://superuser.com/questions/462244/electric-shock-mild-vibrating-sensation-on -macbook-pro-when-charging
- http://www.mac-forums.com/forums/apple-notebooks/278070-electric-shock-macbook-p ro.html
While I don't doubt your particular machine might be lucky, if indeed you have tested as I suggested (laptop plugged in, bare feet on stone/marble/concrete floor), I hope you can see that these incidents are actually relatively commonplace. FWIW, the recent unibody aluminum laptops by HP and Dell have similar complaints too. Which leads me to believe, it has more to do with the metallic unibody design than anything specific to Apple.