My mom wanted a ceiling fan installed and due to her lease agreement, she had to have a maintenance man install a ceiling fan (and pay the landlord $50 for about $10 in labor and $10 light fixture that he will reuse anyways). I was over her apartment for afternoon tea after church, and I heard the maintenance guy short out the wires (The loud pop is so distinct.) I was really mad he did that, but I decided to let it go. Well, I shouldn't have. About 5 minutes later, I smelled smoke.
Apparently, a few sparks set a minor fire on the couch. The maintenance man was nowhere in sight, but I found a burnt piece of #14 on his ladder, so I presume he went to get some THHN or something to pigtail off of what was left.
We reported it immediately to the manager, and I showed him where the wire burned off. Needless to say, she ended up getting the whole job done for free and a new couch and loveseat (my Mom has a huge temper and threatened to sue... I don't blame her.) I saw the maintenance man at the day labor place the next day across from where I work, so I guess he got fired.
So, Even though there's only a slim chance of a fire from a short that lasts less than a second, I say it's not a good idea at all.
My neighbor, the head of maintenance operations at a steel mill, has a device rigged up that draws 50A @ 120V, using nichrome wire. It's about the size of a computer case, and has a momentary switch capable of 75 Amps. Still think it's better to use a circuit tracer, but his idea is better than a dead short.
