I ran into a similar error and this led to me discovering I had two versions of the ghost-cli installed when I ran
whereis ghost
which revealed
/usr/bin/ghost /usr/local/bin/ghost
And I ended up fixing it by following the first two steps in this comment to get rid of the /usr/bin/ghost installation and update the ghost-cli, then exit and re-enter the session so the path picked up the corrected installation.
Edit: I actually had to also symlink the directory to the old path because otherwise I couldn’t get ghost to start. I’m not sure how to fully change it to the new path.
sudo ln -s /usr/local/bin/ghost /usr/bin/ghost