Has anyone ever come across one of these. It literally just pulled off of the wall. On the wall, there is a circular two-tiered, brass piece which fits inside the spout, but has no threads or set screw. It looks as though it was being held on by silicone caulk. I put it back on the same way, and it is drying now. Is this the typical installation for this type of spout? If not, please let me know what should be used. Thanks!