In mystical thought, tramp souls are deceased persons said to be clinging to the material world, often to some locality. They might be holding a grudge against someone whom they feel wronged them.
Alternately, tramp souls are regarded as accidental death victims who don’t understand why or haven’t accepted that they’ve passed.
Tramp souls are allegedly responsible for hauntings, obsessions and possessions.
An unofficial branch of Catholic thinking, expressed by author Michael Brown (Prayer of the Warrior), says homosexuality is in part caused by the influence of tramp souls. According to Brown, a deceased woman’s spirit influences a man’s sexual preference or a male spirit influences a woman’s. So for Brown, an opposite-sex spirit permeates the personality and an individual comes to identify with it over time.¹
The Hindu Yogananda has this to say:
There are, however, a few astral beings known as “tramp souls.” They are earthbound because of strong attachments to the world, and are desirous of entering a physical form for sense enjoyments. Such beings are usually unseen; and they have no power to affect the ordinary person. Tramp souls do occasionally succeed in entering and taking possession of someone’s body and mind, but only when such a person is mentally unstable or has weakened his mind by keeping it often blank or unthinking. It is like leaving a car unlocked with the key in the ignition,- some vagrant may get in and drive off. Tramp souls want a free ride in someone else’s physical-body vehicle—anyone’s—having lost their own that they were so attached to. It was in such cases of possession that Jesus exorcised the vagrant spirits. Tramp souls cannot stand the high vibration of spiritual thoughts and consciousness. Sincere seekers after God who practise scientific methods of prayer and meditation need never fear such beings. God is the Spirit of all spirits. No harm from negative spirits can come to one whose thoughts are on God.²
¹ Brown’s ultra-conservative book also sees the TV show Bewitched as a work of the devil. See Michael Brown, Prayer of the Warrior. Milford, OH: Faith Publishing Co., 1993, p. 103.
² See diccussion » Man’s eternal quest, in the chapter: “what are ghosts?” http://www.yoganandaji.org/board/showthread.php?t=7787