A lot of the "later" GM FWD cars have something like this. Not exactly sure what you want it to look like, but I know a couple here (myself included) use these. No pictures of mine though, sorry.
Essentially (mine) has a couple of lugs on it, I ran a wire from the bat cable (the short lead many have) to it, then from it to the electric fans. Mine doesn't have a bunch of terminals on it, but the other ones I've seen posted here did.
Mine came from what I'd guess to be an early-mid 90's cadillac. The "box" is red, and had an integral cover that snapped over the terminals.
As an edit, it's same in theory to the junction block on our trucks that is mounted to the firewall, just larger.