Okay, this is going to sound weird but I was exploring a space in my attic yesterday and was using my utility lamp. The hook on the lamp brushed up against the metal vent pipe and it sparked and resulted in a burn mark on both the pipe and the lamp hook. Then I brushed up against the attic insulation (it has that metallic paper covering) and that sent an electric current spark as well. The metal drain pipe and the metallic insulation do rub against each other. The lamp is not doing this in other locations in the house. And when I touch the insulation or pipe without the utility light nothing is occurring (I had done this beforehand as I had done many times over the years and not after the sparking incident). So I am wondering do I have a wiring problem somewhere in the walls of my home that is sending a current into the vent pipe? What's going on?

There are a number of things that could be happening..
1. The outlet that you are using for the utility light is defective and it is putting voltage on the case ground..
3. There is a problem with the wiring internal to the utility light and by chance it only happened in the attic.
3. You could have a bad utility neutral and this is putting voltage on you water pipe ground which could be going onto all the pipes in the house .
4. You could have stray voltage from a well pump, electric fence or even from a neighbor and this is coming in through your driven grounds.
Since this is not happen all over the house I would suspect 1 or 2.

Get a extension cord and plug it into another outlet in the house and bring it the outlet in question.. Use the ground on this cord and check each of the holes on the outlet in questions with a electric tester.. you should only get voltage from 1 hole to ground.. the longer one and the round one should show no voltage..

Let us know how you make out and I am sure tk will have more info and suggestions..

Thanks. I'm pretty sure the outlet is okay. It's grounded correctly (I used a tester) and only reads voltage from short slot-ground hole connection. The utility neutral on the water heater looks to be intact as well; it's a new water heater and I can see the cold water-hot water ground connection clearly.
As for the utility light being defective, I tested in the basement (no problems) then returned and recreated the sparking incident in the attic. Conclusion: I think it's okay as well.
I suspect there is a frayed wire somewhere in my wall (not visible from my inspection) that's grounding to the metal vent pipe. While I have a volt meter, I really don't know how to use it to test the pipe.

Use the an extension cord pluged into a grounded outlet and use the tester from the vent pipe to the ground on the cord.. this will read any voltage on the pipe..

When I worked in a paint factory, we had a lot of bronze tools. This was not because I go back to the bronze age. Steel against steel causes sparks. Try the vent pipe with the light unplugged.

Whatever the cause, you need to find it.

I believe you need to test the light with an ohm meter

Test from the lamp shield to each of the plugs

I believe there is a short in the light to the reflector

Depending on way it is plugged in will cause a spark

If you plug it in one way it sparks -- But if you unplug it

And turn the plug 180 degrees it will not spark

The reason is now the neutral is shorted -- no spark to ground

The foil back on insulation was probably grounding to something