That can be a real pain. A metal coat hanger or better yet if you can find an old stainless steel antenna rod that is very thin works well. We kept many in our shop. Hangar wires are not flexible enough in some cases. Check at a local CB shop to find an old one.
In some cases you can wad a bit of duct tape onto the rod so it has some sticky all over and get it to grab but mostly a small hook on the end is what will work.
IF you can actually pull it all the way out from the bottom you should then be able to fish a line from the top, tie it to the wire, and then pull it back up. It takes two people for this trick most often.
For someone that does this a lot a speedometer cable is the trick. Very flexible and they don't often snag.
