Okay first, i would i freak too, but maybe the man was trying to tell you something, do you believe in spirit? if yes maybe that’s the reason why, probebly is family dont really bother or dont really believe in ghost, so , like they say if you dont believe, you wont see it. Maybe this old man was trying to tell something, he died but is time is still not come, he have something too say, if you ever see the man again, try to calm down ( dont worry i know it most be sacry, cuz your not sure what he want or what he will do). By the way did you feel like it was a bad feeling when you saw him? Or you were just scared cause he walked you up?