It's a flasher.
And if the original clip is missing, just nylon-tie or Velcro it to something that will keep it out of trouble.
If people have been messing around in there, installing and wrecking out stereos, etc., all kinds of original clips, arrangements, and routings may have been changed or eliminated, so just try to make it neat and accessible, for the next time you have to mess with it.
Because when you do a crappy job and figure, "Screw the next guy," you yourself always end up being the next guy.
– Eric