I've taken the revised haunt rules from somewhere on the boards here, along with revised statistics for the PF2 haunts that are also on the boards here somewhere.
So, if I understand this right, a haunt will act on initiative count 10 in a surprise round. However, there's some subtle manifestation where either the character assigned to the type of haunt or, at a -2 penalty, a character that can either detect undead or channel energy can detect. So, if you meet the DC, you pick up on the clue before the haunt effect is triggered.
If that person(s) beats the Perception DC, then they usually notice some spooky sign: a child sobbing, a piano playing a few notes, etc. If a Channel Pos Energy character can beat a 10 on the surprise round, he/she can spend a channel energy use and try to do enough damage to take out the haunt. Otherwise, the haunt is triggered like normal.
Is this the proper sequence for resolving haunts in Pathfinder? And is there nothing else other than Channel Energy to stop a haunt?