I believe, No human being alive on this planet can answer this question.
It could be a YES or a NO. Any person who would say that they do exist or they don't exist, that would act as a meaningless answer without any valid proof.
Using the same knowledge that builds bridges, generates power and allows acrobatic artists, we know that ghosts do not exist. Unless you can show one example where energy is created from nothing, then you can't prove ghosts are real.
If you want more proof, take a course on physics.
