They guy who owned this house was an electrician, plumber, and HVAC contractor, so there are all kinds of interesting things here - some cool and some bizarre. Today, while putting in a new garage door opener I came across this. Sorry for the bad picture, I cut out one of the nails.
So what you are seeing is a 20 penny nail driven from outside in, through the framing around the garage door with a piece of lamp cord soldered to it and wrapped in electrical tape. There are two of them (sorry I took such a crappy photo) about 3 inches apart. The lamp cord runs up into a wall and goes who knows where.
I'm thinking maybe he wants to open the garage door from outside but he doesn't want an obvious switch for a burglar to use, so he did this so he could short across the nails and open the door? I dunno. It was done so long ago there are multiple coats of paint on the nail heads outside.
Any guesses?