Yup - they are created during the process of adding Z-Wave devices to your hub, when the join process doesn't complete properly.
You'll need to remove those ghost devices, and re-pair the devices to your hub.
Remove power from those devices and then use the Refresh button until you see a Remove option, and hit Remove. May take multiple tries of both the Refresh and Remove buttons for it to work.
If you don't remove power from those devices the hub will still be able to ping them and won't remove them. Many switches have airgaps you can pull out to kill power to the switch w/out having to hit a breaker.
If the hub removal process doesn't work you will have to go this way...
