"Demon activity appears to be on the increase, varying in degree and form from place to place. The more prevalent that spiritistic practices are in a certain area, the more problems there are likely to be with demon afflictions and harassment.
The attack by wicked spirit forces can take many forms. From actual cases, we know there may be physical attack, as well as mental attack. There may be a bodily blow, a slap in the face, a throwing of one to the ground (Mark 9:17, 18), bodily illness and pain, doctors being unable to find a cause. (Luke 11:14; Mark 1:26; 9:25;, Matt. 12:22) One may be disturbed while trying to sleep, due to the prevalence of abnormal noises in the house. There may be a tugging of bed covers, a shaking of the bed, an apparition such as a face or a pair of vicious eyes. Often a 'voice' is heard that harrases and terrorizes. The voice usually suggests or commands a certain course of action, which, if followed, can lead to spiritual collapse, violcence, insanity or suicide." - The Watchtower December 15, 1966 "Repelling THE ATTACK OF WICKED SPIRITS" pgs 739-744
Foolishness and idiocy right from the horses mouth. This article scared the $HIT out of me for years as a child. My mentally unbalanced, ultra spiritual witness mother believed this 'hook line and sinker'!
Read the entire article and you will see why there are so many 'crazy' Jehovahs Witnesses.