If "haunt" means to visit or appear as a ghost:
* Leave
* Depart
* Disappear
* Vanish
* Fade
* Pass on
* Go to peace
* Find rest
If "haunt" means to trouble or worry persistently:
* Comfort
* Soothe
* Reassure
* Ease
* Relax
* Liberate
* Free
* Release
* Unburden
If "haunt" means to frequent a place:
* Avoid
* Shun
* Leave alone
* Stay away from
* Ignore
* Neglect
If "haunt" means to stay in one's mind persistently:
* Forget
* Dismiss
* Eradicate
* Suppress
* Banish
* Purge
* Let go of
The best antonym will depend on the specific meaning of "haunt" in the context you are using it.