If there would be a distribution of dark matter that explains the poltergeist, we could measure that distribution of dark matter.
We can measure the mass distribution on astronomical scales. We "see" the dark matter. Just not with light.
We can measure the mass distribution on astronomical scales. We "see" the dark matter. Just not with light.
It's not crazy different from saying the same about that poltergeist.
We know of particles which behave the same way. Neutrinos for example.
We are not measuring dark matter, we are measuring something that is not what we expect and we decided it's dark matter.