The best explanation of why ghosts mostly appear at night is perhaph because most people are scared of the dark since they can't see anything and imagine things to be there that aren't . However , there is a science-besed theory too . The earth's atmospher is bombarded by solar ardiation from the sun more during the day than the inght . 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 it's easier for them to manifest at night .