Yes, they are! I would like to explain my point of view on this question from metaphoric angle. Ghost in this context, I presume is preferring to those people cause us harm emotionally and psychologically. Today, so many dreams have been truncated due to the trust betrayed by our loved ones.
Now, for my point to be driven home properly, there is need for me to touch key areas of our live to buttress it. Proverbially, it's only the rat that is familiar with one's house that can go and tell the outside ones there's food inside the house. it's obvious that nobody can cause us hurt except those that are close to us.
Additionally, familiarity they say breeds contempt. And nobody can make you look inferior without your consent. If truly, we want to remain unhurt by keeping ghosts at bay, we must strive to make sure we are careful of those we allow into our circle of influence. With this simple principle, we can prevent ghost-like betrayal and backstabbing from those we call our loved ones.