http://www.markbeiser.com/HVAC/WOS/electricalhacks/elektrishun5.jpg

I didn't know that plumbers perforated tape was thick enough to provide the required protection. Learn something new everyday.

Never let plumbers touch wire. Also, never let the guy who did this installation touch wire. Infact,don't let anybody related to him touch wire either. In fact...

Well, when the homeowner wants to hang a shelf and his nails keep getting bent, he's just going to reach for a drill anyhow- this saves him the trouble!

There's more pics... take the 5 off the end and replace with a 1, 2, 3, 4.... Someone doesn't realize that outer sheathing is supposed to enter the box too!

Well as long as the sheetrockers have good aim...

I like this one

http://www.markbeiser.com/HVAC/WOS/electricalhacks/elektrishun2.jpg

So do those wires now have a free air rating?

Well, homeowners need to understand that when their nails don't penetrate and only get bent, that they are in fact hitting protective metal. That there's wiring or pipes behind it that could get damaged. And that they must give up on that spot, and nail elsewhere. And also not to use very long nails that they might happen to have a supply of...

Of course, being perforated tape, Murphy would make sure the nails went thru the hole and into the romex :-)

You can hardly make anything foolproof. I've seen people repeatedly drill into steel gas piping - they didn't make it all the way through, but the pipe had noticeable dents.

Funny that you mention gas pipe.

In an old 19th-century tenement that my uncle lived in at one time, there was a gas jet on the wall in one of the rooms. But my now 60-year old uncle didn't know what that thing was - he had never seen one, having grown up in a city in Colombia with electric lights, candles and the occasional kerosene lamp.

Since he wanted to put some furniture against that wall, he decided one of those days he was going to take a hacksaw and cut the pipe off and then plaster the hole over.

One day he and the building super were talking and my uncle happened to mention this funny pipe sticking out of the wall and that he was thinking of cutting it off.

The super got scared and said "Don't cut that off!! That's part of the gas!" Then he went on to explain to my uncle that the building was from before the days of electric lights, so those pipes were for lighting up the room with gas flame.

Reminds me of the gas tap in our bathroom... or precisely the WC. High up just below the ceiling we had a piece of steel pipe coming out of the wall with a brass valve at the end.
I didn't really think that was still active, but thought it MIGHT be. So just for fun I opened the valve... and at the resulting hiss quickly closed it again!