You... Don't get how the burden of proof works do you? I'll break this down. The burden of proof lies on the side making claims against the Status Quo, the baseline of the topic. The baseline being that the positive, does not exist as part of the baseline. In your example of Ghosts, the baseline is that we live in a world where they don't exist. Even if I'm the one claiming that they don't exist, the burden of proof is not on me to disprove them. It's on the other party to provide empirical, indisputable proof that speaks contrary to to the baseline. That's the only way that the Burden of Proof works, otherwise you could make Valid arguments that Dragons, Dinosaurs, Unicorns and, well, anything else in the world be it real or not are still running around and it would be taken as fact and made into a common truth.