But I can't prove if it was super natural or not, so ¯\_(ツ)_/¯ I really can't say...
I think that's the trick of it there- we can't prove ghosts exists becuase we can't fully define what a ghost IS. Are they conscious, or leftover energy? What are they made of (on a molecular level?) Without having something concrete to test for, 'ghost hunting' consists entirely of the debunked, and the unexplained. It's impossible to say for certain if that's becuase we haven't figured it out yet, or if it's just not real at all.