According to two researchers, Michael Jawer and Marc Micozzi, MD, PhD., sensing a presence, seeing an apparition, or feeling energy around a person or place may be related to the workings of the limbic system--the "emotional brain"--as well as a personality type that rapidly registers feelings. A reputedly "haunted" place, therefore, could exhibit stimuli that register more with certain people and less with others.
http://www.scienceblog.com/cms/blog/8375-haunted-people-potentially-explained-mind-body-basis-anomalous-perceptions-26531.html
That is interesting Brian. Needs more study on people who are sensitive. I would like to see more research on people projecting thoughtforms.