whether you believe in ghosts or not, you have to admit that stories of ghosts exist all around the globe The best explanation of why ghosts mostly appear at night is perhaps because most people are scared of the dark since they can't see anything and imagine things to be there that are not. However, the a science-based theory too The earth's atmosphere is bombarded by sotar radiation from the sun more during the day than the night During this bombardment, atoms in the atmosphere lose their electrons and become ions that restrict some forms of electrical activity in the atmosphere Ghosts are believed to be energy based manifestations so its easier for them to manifest at night