Is it bad that my MacBook Air is passing me electricity? Whenever my MacBook Air is connected to the AC power and I have my hands on the palm rest, I feel it passes some electricity to me. If I unplug it from the AC power it stops doing that.

This has recently became obvious, when other people can feel this tingling by touching my skin after I've been working for a while.

I have two questions:

1- Is this normal in unibody Macs?

2- Is this harmful for my health in the long run?
Electrical current passed from e.g. a MacBook Air can be avoided by plugging your Mac into a grounded power outlet. I sometimes get this too when using a non-grounded power outlet.

I am assuming you are referring to being able to sense "vibrations" as you e.g. slowly and lightly move your fingers upwards on the palm rest?

I have found that when I have my Macbook Pro plugged into a non-grounded outlet and I touch something that grounds me - e.g. a radiator, I can feel the vibrations. If I stop touching the radiator, the vibrations cease!