Establishing that would be helpful, but is not necessary to get started.
Either there’s more weird stuff in this house than outside of it, or there isn’t. If there is, that should increase my confidence that there’s something weird-stuff-related in this house. If there isn’t, that should decrease my confidence.
If I’m confident that ghosts are weird-stuff-related, the second case should decrease my confidence that there are ghosts in this house, and the first case should increase it.
Establishing that would be helpful, but is not necessary to get started.
Either there’s more weird stuff in this house than outside of it, or there isn’t.
If there is, that should increase my confidence that there’s something weird-stuff-related in this house.
If there isn’t, that should decrease my confidence.
If I’m confident that ghosts are weird-stuff-related, the second case should decrease my confidence that there are ghosts in this house, and the first case should increase it.