[Knifeblade]

Well, you can try a cheap fix. Get some very good two-part epoxy, follow directions, and bond the fixture back on. Use puhlenty of tape to hold it in position while the epoxy cures, around at least 12 hours.

That's the low-budget fix, but the best peace of mind fix is to just get a new fixture. The cable isn't that hard to disconnect, as it attaches to the mirror, and the cable/mirror assembly will unscrew out of the fixture.