In 1967, a law office, a place called Rosenheim suddenly started receiving mysterious phone calls with no answer on the other end, lights in the building started to act strangely- they would swing on their own accord, and turn on and off. Soon, the workplace photocopier started to leak for no apparent reason. Eventually, the office cut of all power and used a standalone generator to get electricity, the strange phenomenon continued.
People began catching wind of all the strange going on's, and began interviewing and doing research. Upon interviewing, they came across a teenager- Anne-Marie, they concluded that she was highly strung out, and very emotional (had repressed anger and disliked her work and employer).
Researchers began to notice that the phenomenon only started at certain times of they day, coincidentally when she was working. They noted that as soon as she stepped in the office, the strange happenings started, and as soon as she left, it ceased.
Anne-Marie left her job soon after, and the phenomenon in the office stopped completely. It was documented that she had several other jobs in which the strange electrical problems followed her.
Researchers and Investigators never learned weather it was simply a hoax or a real life poltergeist case. But what makes this case so fascinating was it can't be explained if Anne-Marie was so troubled she could have created this herself. Also, it was one of the most documented Poltergeist cases on record and not just by one group, by electricians, telephone repairmen, physicists and researchers. All to which could not really pinpoint the root cause.
Unlike most Poltergeist stories I have read- that haunt specific places or houses. This certain case picked a person, and stayed with her. Weather it be her creating it as a hoax, or an actual happening. The answer is still unknown.