Passaway Caves has 7 wild species on its encounter table, appearing between level 6 and 9. Rates below are the chance of each species when an encounter triggers, not the chance of an encounter itself.
The wild Dokimon you can find here are Casper, Soul, Luna, Yomeshi, Jolleek, Haracker, Jespurr. The most common encounter is Casper at 26.7%; the rarest is Jespurr at 6.7% — worth knowing before you settle in to hunt one specific spawn.
Ghost
Dark
Light
Fighting