With the update of Safari 12, all extensions using legacy code have been disabled. We have built a new Ghostery Lite extension that will work with the updated Mojave/Safari 12 release. However, its not in production yet. For now… Here are the instructions on how to reinstall Ghostery 5.
1) Open Safari
2) Go to Preferences in Safari
3) Select the ‘Extensions’ icon
4) Find Ghostery in the left panel
5) Check the box near Ghostery
6) A message will pop up saying: “Are you sure you want to enable the extension ‘Ghostery’“, then select Enable
7) You’re good to go!