He exerts his influence over the body
Prabhupada looked at this man and quoted from the seventh chapter of the Bhagavad-gita, “bhumir apo ‘nalo vayuh kham mano buddhir eva ca.” Prabhupada described the different elements and explained how the mind, intelligence, and ego are subtle energy. Prabhupada was speaking to all of us, but he was looking at the man. Then Prabhupada began to speak about ghosts. I didn’t think anything of it at the time, but Srutakirti, who was sitting on the floor on Prabhupada’s left, chuckled and said, “Prabhupada, why are you talking about ghosts?” I was taken aback when he asked that question. I thought he was being too familiar, but he had a familiar relationship with Prabhupada. Prabhupada ignored the question and continued looking at the man. Prabhupada described how ghosts are subtle, how they don’t have gross bodies and how it’s a very sinful birth. A ghost has material desires but cannot fulfill them through a gross body. At one point Prabhupada said, “Because ghosts are powerful, sometimes they move things,” and Prabhupada moved his hand through the air as though he were moving a glass. We began to realize that this man was ghostly haunted. He was studying the science of the mind, but somehow or other his mind was overtaken. I got enough courage to ask, “Prabhupada, if a ghost overtakes someone, does that mean there are two souls in the body? Does the ghost’s soul enter the body?” Prabhupada said, “No he doesn’t go in the body, but he exerts his influence over the body. The ghost doesn’t actually enter, so there are not two souls managing the body.” That was an unusual experience.
Source: Remembrances by Sidhanta Das – Folio Vedabase