After much research, I found the solution for getting rid of the ghost printer in the following post: How do I get rid of a ghost printer in Gnome?
The reason for publishing this post is that a new version of "avahi" was released this April (2018) which overwrote the "/etc/avahi/avahi-daemon.conf" file. This recreated the problem of the ghost printer. Fortunately, I remembered how to resolve this problem. But tweaks, after a period of time has elapsed, are easily forgotten. Finding the solution again can be frustrating and time consuming. Hence this post. Below is my addition to "/etc/avahi/avahi-daemon.conf" file as recommended in the post cited above to eliminate the ghost printer.
Note: Prior to overwriting the "/etc/avahi/avahi-daemon.conf", the "avahi" upgrade does ask for permission. I let it overwrite the file as I wanted to see if the new version may have resolved the ghost printer problem. It did not.#----------------
#restart service with; sudo service avahi-daemon restart
Also when adding tweaks, I tend to add comments that identify where the tweak originated, other useful comments, and the date it was inserted.
I am also using Ubuntu 16.04, so I don't know if this ghost printer problem exists in other Linux distributions.