I believe it is possible for the human mind to manufacture evidence for whatever it believes exists, however, be careful what you allow it to manufacture, it may not turn out to be best for your health or actually exist.

I have witnessed what I would call apparitions. I think it's important if you're experiencing that phenonenom, to differentiate what is real from what is perceived to be real. You sound like you're giving the apparition more power than it actually has. It isn't going to come to life and cause you harm physically, but, are you able to find a deeper meaning for why exactly you are seeing this form of apparition? What is it trying to tell you? What can be learned from it? It's important that you guide your energy and thoughts positively, towards a healthy outcome.