I'm also an Atheist, meaning I don't believe in any gods, however that does not prevent me believing in ghosts and spirits!! but as it is I don't believe in any such thing!! I would love to think their are spirits or ghosts out there, the world and his wife seem to have seen one, nearly everybody I know has seen one. I put this down to the fact that I'm not so gullible and I don't have this desire to have to stand up and say Ive seen a ghost!!
I have lost family members in dreadful circumstances and miss them dreadfully but I have no illusions of them burning in hell, living it up in heaven or about to pay me a visit a a ghost or spirit, all are equally preposterous.
I'm sure people will say I have never seen ghosts because I'm not receptive, I say Its because I live in the real world!!