Sparks when plugging external monitor in

Are you using the MagSafe adapter with a two-pronged plug or the three-pronged power lead (I'm suspecting an Earthing issue here) ?

In addition to the other suggestion, I recently went through this and the problem ultimately required rewiring of the service to my house. There was a poor earth-neutral bond.

If the 3-prong adapter doesn't do it, I strongly recommend that you have an electrician check things out as this could be a potentially hazardous situation.

Luck-

-DP

We are referring to the plug that plugs into the mains power. If the 4-way socket is not grounded properly you could get sparks.

The sparks are indeed indicative of a condition that could potentially damage your laptop and/or monitor.

Luck-

-DP

"Sparks" are never considered normal!!!!

+Just tried it plugged directly into the wall and its still occuring+

The key question is, has the MagSafe power adapter got the full length lead and 3-pronged plug on it or just the smaller adapter that just slides onto it - the first (should) deliver a proper earth connection to your MacBook Pro the second will not.

Right, so this really confirms it's most likely an earth issue ...

As I said before, you need a licensed electrician to take a look at your wiring. If you are in a rental unit have the manager call the electrician in.

I have been through this. Fortunately my house was being rewired anyway because of a remodeling project, and I had sparks all the way up until the day the wiring was complete.

Luck-

-DP

Was the wiring in your house done by Halliburton?