Hi
I don't doubt there are spirits that haunt cemeteries.
A friend of mine recently left his voice recorder active on his phone whilst visiting a local cemetery.
When he played it back he had a varied of voices speaking .
He actually played the recording to me and you could distinctly here a voice say ' Cold '
And another say 'help me '.
This was a very quiet cemetery where there was nobody around but himself.
Some spirits may be still attached. That could be their body, their ex home, even a personal belonging. Whether it'd be actual them or fragment of
them left behind, that said to be imprinted into the body as a vessel, the structure they resided in most or enjoyed to the object they cherished.
From my experience and research if cemeteries are haunted it's not necessarily by the deceased buried there as they have died elsewhere and have other
places that they would more likely to haunt if they were to linger after their deaths. Many have also had full funerals held by their families are
supposed to be "at rest".
That being said there could definitely be OTHER entities that are drawn to these places as cemeteries would be full of strong energies and negative
emotions.
My home town in Southern Indiana has a haunted movie theater that I used to work at when I was a teen that was literally right next to an old
cemetery. (People from the 1800's buried there and I also remember my dad saying that some of these old cemeteries were placed close or on top of
Native American burial mounds).