I would offer a different prospective to a true haunting. A nomad theory, a lost soul entering and exiting our plane of existence like a nomad. My belief is all souls are a ghost, spirit or entities at the time the body ceases to exist and that they flow through us and are environment because that is where their energy truly exists due to their love for life.
Their energy is not created with death but the grasping of a life they once knew.
My belief is we all have one true moment of Joy, a child's first walk in a yard, a special little laugh while cuddling with your wife. This is where our spirit needs to rest, an earthly heaven so to speak. It is the spot we are safe and comfortable. It is an impression in our soul that shaped our behavior while we lived our lives and made us comfortable with our final resting place when passed.
But what if the happy moment was 30 years ago in a house long ago demolished. Will this spirit roam and roam becoming more frustrated? Flying in and out of the paranormal sensitive areas? What if it finds the house or area they was happiest in and does not recognize the family?
I would hope all can find there special comfort zone, and assure all believers of the paranormal that a ghost is and once was a loving soul. The malevolent behavior, could be that of a frustrated lost and lonely soul that just needs to be comforted and guided. However I would not disregard or confuse this theory with that of a demonic haunting or possession, but only offer it as a reasonable theory to abnormal activity that surrounds us.
It is but a belief that puts a smile on my face when I hear the pitter patter of my beloved Poohbear's paw on our hard kitchen floor late at night. Or when mysteriously I do exactly what my long passed dear grandpa would of done, even when it is not the popular choice.