My bathroom mirror

At least once every day, I walk past my upstairs bathroom mirror and there is someone else in it though there is no one standing beside or behind me. I avoid looking in it now for long periods of time (making it fortunate that I also have a downstairs bathroom). At first- meaning when I first moved in, It would only happen in the early morning hours and it would be a man trying to see around me to shave his face, who would promptly disappear when I turned around. Now, as I do not get up in the early morning hours due to my odd work hours, he appears all of the time, usually just beside me when I walk past the mirror in the hallway near my bathroom. Whenever I look in it for a long period of time, he shows up behind me, and my face warps for a few seconds into someone else until I look away.

It is not malicious, but rather confusing, and can be annoying when I am trying to apply makeup or brush my teeth. I never did like mirrors.