^The issue is not whether ghosts exist or not. You can't prove a negative.
The issue is whether anyone on earth has any reason to believe they do.
The answer to that is no^
I disagree, I absolutely believe that ghosts exist, but they are not spirits of the dead. They don't exist in a way that can be measured or proved by science, in the way that dream images can't be projected directly from the sleeping person's brain onto a screen. It doesn't mean that the dream doesn't exist or that the person hasn't properly experienced it.
I absolutely believe in people's experiences but put it down to imagination, atmospheric/environmental conditions, electromagnetic fields, low frequency sound, drugs, alcohol, being asleep/semi-conscious, collective hysteria, grief, or another function of the brain.