Are Ghosts evil?

When this world is viewed in the context of greater reality concepts of good and evil vanish, becoming instead opportunities for experience and growth. Most ghosts certainly aren't harmful, but certain trapped entities do carry considerable anger which prevents them from moving into the light. An encounter with such Spirits may be disturbing, but is unlikely to be physically harmful.
There are also mischievous Spirits. They may be immature entities, or simply playful. Typical evidence of these is losing things only for them to turn up in unexpected places some time in the future. A more extreme case might be blankets being pulled off your bed in the night.