This was a solution I came up with to a very specific problem I had when setting my garage up for EV charging. I have no idea if anyone else will ever run into the exact problem a second time, but on the off chance they do I figured I might as well share the work. 

Basically the only outlet that would really work without requiring a cable extension for the charger was located on the ceiling, directly above where the car would be sitting during charging. I needed a good way to run the heavy cabling along the ceiling that would make sure it didn't get run over, but could also be easily pulled down if I needed to bring the charger with me on a longer trip. So I came up with this bracket using a pair of ½" x 3/8" screw-in cylinder magnets that I had on hand from some other projects and some standard nylon zip ties to firmly attach the cable to just about any metal surface. The magnets linked are quite strong, but not hard to pull down when needed. And because I was working fast and wasn't too concerned about getting exact measurements it's also big enough to handle lower gauge cables or a garden hose without kinking it.

They're designed for printing in PETG using a fair bit of infill for strength. In addition to the zip ties and magnets linked above you'll need some #6 wood screws. I also just cut off a bit of steel bar stock to screw into the ceiling in a spot where there wasn't a handy magnetic surface - but you could probably accomplish something that would work just as well with some carefully arranged washers or the like.