@TooBigForMyBoots
Definitions are one of the simple tests they fail.
Again, the onus isn't with the sceptics to disprove claims, it lies with the people making the claims to come up with definitions, hypothesis, repeatable experiments which demonstrate the viability of their hypothesis and so on.
I think the reason that otherwise enormously intelligent and inquisitive people can't or won't do this with ghosts, the divine and so on, is that the formulation of any hypothesis fails at a very early stage, so the obvious conclusion is that these things do not exist as part of our universe.
If you suggest that you have been visited by a dead relative, you don't just have the problem of putting forward a convincing argument for whatever you witnessed being a manifestation of your dead relative, in fact, that's rather secondary. Where has this manifestation come from? Why does it only appear to you? How does it materialise and dematerialise? Where does it abide when it is not busy scaring it's former relatives, and what is the nature of this 'place' it supposedly inhabits when it's not here? What is it composed of? Why are these phenomenon totally resistant to being recorded by any normal means? Why do only some people ever encounter these phenomenon? Why is it that this phenomenon does not mesh with what we understand about the nature of our universe, and more importantly, if this is what the 'believers' purport it to be, it throws our understanding of the universe into complete disarray and contradicts already well understood and demonstrably viable hypothesis.
So which is it? That nobody who 'believes' in these things is capable of formulating a single hypothesis that satisfactorily answers any of these questions, despite the human race being able to do just that for equally as perplexing and nebulous phenomenon, or is it quite simply that it is impossible to propose any viable hypothesis at all because the things that are being claimed simply do not exist, and contradict so many demonstrably valid prior hypothesis that they are patently absurd?
You keep asking about what 'science' says about these things, how it defines them and so on. The reality is that science says nothing much about them other than that they do not exist, because there is no credible evidence or reason to believe that they do which actually stands up to scientific scrutiny. What more are you expecting? I'm sure if there was any validity to these claims at all then there would already have long been teams of scientists postulating this or that and submitting their theories for scrutiny, yet science appears to be perfectly comfortable with it's conclusions about the existence or otherwise of 'ghosts' and such, despite people all over the world still claiming to believe and witnessing events they conclude are down to the paranormal, in spite of the fact that there are invariably far more satisfactory and credible explanations.