The cable is plugged in to the back of the printer. With the end that you plug into your computer hanging loose, I get a subtle shock when I touch my skin against it. It does this with the printer power on or off.

What causes this and does it need to be fixed?

 

Sounds to me like a case of....

But seriously. What do you expect a powered interface to do when you contact the ground to the power via your skin?

 

It means you have thin skin.

 

Lick it!

 

Stick it in your pooper.