The problem is that we keep taking colloquial statements from non-scientific people we disagree with and pretending they are properly stated hypothesis to build a strawman so we can feel better about our intellectual superiority.
Finding 'what the heck is going on here?' is the most basic of scientific endeavors, yet the comments here overflow with predetermined conclusion on the theological question of ghost-existence, with a notorious absence of interest in any actual facts or potential evidence for the 'haunting' phenomena. This reflex is precisely why so many non-technical people think science is just like a 'secular faith with its own beliefs'.
To pick an arbitrary example, no doctor would work like that and claim its scientific:
- hey doc, I spent all day in the rain and got a flu...
- you're an idiot, you can't get the flu without being in contact with the virus. Now get out of my office unless you can really prove you got it from standing in the rain!
Instead, the doctor would extract the core of what the patient (not assumed to be a doctor or a scientist) actually means ('I feel bad, like when I've had the flu before'), interrogate the patient for the facts and details (symptoms, timelines, contact with other sick people), and translate that into a useful hypothesis for the disease and its cause... and at least go through the process before yelling hypochondriac.
Of course "there are ghosts" is not a useful scientific hypothesis.It's actually not a question of falsifiability, but specificity: 'ghosts' is not defined well enough to even get to the falsifiable part. Like 'god' most people in a conversation don't mean the same thing with that word, and a *lot* of people won't mean the same thing at different times in the same conversation.
But the people saying 'there is a ghost in this house!' are rarely trying to build a scientific hypothesis, or are even trained to do that either. They apply 'ghosts' as a shorthand for 'something weird is going on' and a blind jump of faith to a lot of cultural baggage of 'stuff people have said in the past was related to similar weird stuff', as a way to communicate that 'unknown' experience through a common meme. Much like people have always done when other stuff happens and they guess at some pattern: health and sickness, weather, economic hardships, magnets, etc - and people are often wrong when they do that, but that doesn't mean there was no phenomenae to feed those memes in the first place.
Maybe an investigation finds nothing more than construction defects, bad insulation, gas leaks or defective electronics - if it was fun enough to spend the time, so what? Maybe it finds something more surprising than the usual (without requiring theological explanations).