Let's see...there have been so many ofer the years...
How about a condom as a vacuum-through-the-conduit mouse for a pull-string.
We've all used coathangers as short fish-tapes. (Haven't we?)
My son. (He admits that he's strange - brags about it, even.)
I know someone who actually used his pet ferret as a ferret to pull a string over a ceiling.
Cell-phones as walkie-talkies (not in walkie-talkie mode - we have unlimited calling.)
How about using a reciprocating saw to shake loose a stuck pull chain?
We had to install several recessed lights in an insulated ceiling, but these particular fixtures only came in a non-IC version, so we improvised: we made 1-sq-ft "cages" of 1/4" steel mesh. The inspector loved them.
We have many food containers as hardware jars for wirenuts, staples, screws, etc.
Hmmm, what else? Okay, a really, really off-topic one, except it was for a work van. Because of zoning, I had to cover a temprarily-off-the-road van in my driveway. The law requires a form-fitting cover, not a tarp. Van covers are expensive, so...
I used large stainless-steel safety pins to "stich" together a fitted cover from a tarp. I closely-fitted the seams down each corner, folding the resulting flap to one side. Then I peeled the cover off, turned it in-side out and pulled it back onto the van.
When it came up (and, of course, it did) that it was a tarp, I argued (civilly, of course) that the law doesn't specify (a)the material type, (b) what the seams have to be stiched with, or (c) that it must be store-bought.
It was allowed.
Larry
www.fineelectricco.com