The thing in the graveyard

My home is opposite to a graveyard, one day at 4am I opened the door and looking for my uniform.My house is built with three houses.We are second .When I was searching for clothes I discovered that something is wrong beside the three house .When I saw there ,I saw man of fully dark black seems like a real ghost saw at me and ran away .When I looked at the place no one was there . Who is that mystery character that I saw ? Is that a human or something else,..