An intelligent spirit is one that has passed on but can communicate with the living. There are many theories put forth to explain why intelligent hauntings occur. Some experts believe that spirits who choose to remain among us do so because they are attached to someone or something. Or it is possible that they are confused and are not aware they are dead. Another belief is that they have some unfinished business to attend to before they can or will move on. In any case it remains a mystery why a spirit chooses to exist among the living.
Unlike a residual haunting where one experiences lingering energy, intelligent ghosts do interact with the living. In fact, intelligent spirits will go out of their way to get the attention of the living. Intelligent spirits tend to be assertive, although this does not mean they are dangerous. They just carry on with the personality they had in life, if they were nice they remain nice, if they were angry they remain angry etc.
Some signs that it could be an intelligent haunting are windows and doors being locked or unlocked, lights going on and off, items being taken and then found later in an odd place, voices that join the conversation, strange cold spots.