Haunters are rather categorized as demons. Why?
They haunt an individual or item.
Most reasonings, being their emotional tie to it.
If their emotions are so strong about a person, they become stalker-like spirits, following, watching, hearing every move. Either they stay invisible or are VERY visible, depending on how emotionally charged their attacks are.
Said spirits, have no signs of angel- or demon traits. They are their own middleground, from the middle, the spirit-plane.
Some, who have malicious intentions, tend to have blackened scleras, due to all their hate seeping through, getting purged by tears slowly. It can take a week or many centuries, all dependant on how forgiving and petty the individual is.
In case of specifically a person, which they haunt, notices them and their malpractices/pranks, they can attempt to communicate with them, in order to compromise/help/settle a conflict with them, so they can move on and the person in return, will stop getting haunted.
If a spirit is bound to an object they haunt and a person owns them, the spirit can be malicious and break things around it, just because its peace could've been disturbed, by you setting it on a windosill- or living somewhere noisy. Yet again, pettiness depends on the spirit, how they choose to act. Some spirits might come to rest, if you choose a cozy place they like..
Sometimes, a spirit will beg you to break something, they could be (in)voluntarily bound to, in order to find peace.
Due to Haunters (nicknames from other spiritual creatures given them, as a general term shared by many), exorcists, religions and also the job as ghost-hunters thrive. They unintentionally fuel an industry, just like with mobian-birds, just by their mere existance.
A spirit can become very enraged, if they realise there's an exorcist/ghost-hunter there, to rid them off a person/object. If their job has been done well and successful, they get put to rest.