What is an example of dark energy?

All haunts of an evil order make themselves manifest to us through the medium of darkness because darkness is more in harmony with their rate of spiritual vibration than is light.

Ghosts or haunts that belong to a certain plane of life―or number of vibrations per second may be seen by animals, especially by those animals that see well at night because it is by night that ghosts of this particular land are to be seen.

Fragments of Spiritual Knowledge Pertaining to the Spiritual World