What would make you think it wasn't some easily explainable phenomenon such as hallucination, optical illusion or countless other situations? In your case you say the figure was "human like", this implies it wasn't clearly a human, just something sort of looks like it could possibly be human. An optical illusion of course wouldn't likely produce something that would look like a crystal clear human figure but instead would produce something like you saw which would to someone look human like but not clearly human. Also in your situation like almost every other it occurred in a dark room where there is a very low signal-to-noise ration for your vision which leaves a lot more of what you see to your imagination than in a regular situation. Once again, think i mensioned it on first post, in a pitch black room, human like figure just appears from wall and walks across the room, the nose was the most clear feature on the face, but most other things were a blur, and my friends saw it as well.