Quantum entanglement suggests that if you have two particles of the same atom and separate them, then their behavior will be the identical, even if you send one light years out into space. Possibly even if you were to separate them through time.
Could this be a possible explanation for ghosts?

 Robert Ripley of the Believe It or Not fame died while filming the 13th episode of his tv series. He just passed out and was pronounced dead of a massive heart attack. The episode's story line: stories of death and death rituals from around the world. Believe it or not!

The known is finite, the unknown infinite. - Thomas Huxley

There is an area in Wyoming where Shoshone and Crow indians once told legends of tiny people that they called the Tiny People Eaters. During an investigation of a cave in the Pedro Mountains in 1932, some explorers found a tiny seated mummy that measured at 14 inches. These stories were also told by the Sioux, Cheyenne and Arapaho indian tribes. As a matter of fact, these legends were spread all over the US before European settlers ever arrived. The mummy was lost after trading hands several times, but it was checked by a few schools and scientists during its time. The American Museum of Natural History allegedly x-rayed the mummy and found a perfectly proportioned skeletal system and overly pointed canines. They also said it was killed violently with several broken bones and a blow to the head. They said the little man was about 66 years old when he died. These were said to be certified genuine by the Anthropology Department of Harvard University.
Another story says that the University of Wyoming studied it and said it was a diseased child who died of natural causes. Which one is true is hard to verify since the mummy disappeared in the 1950's.

Ed Gein was a serial killer from Wisconsin. He was known for skinning his victims and using their skin in various ways. Including making woman suits that he would wear and pretend to be a woman. He was arrested finally and declared insane. Why they didn't just shoot him is beyond me. He died of complications of cancer in an asylum in 1984. After Robert Bloch wrote the book Psycho and based Norman Bates on Ed Gein, he became a "celebrity". His story was also the basis for "Texas Chainsaw Massacre" and "Silence of the Lambs".

Teddy Roosevelt wrote a book containing a story about an encounter between a Bigfoot and a German fur trapper named Bauman and his friend. It occured in 1892 around the Salmon River in the Bitterroot Mountains between Idaho and Montana. An area still rich with Bigfoot tales. 

Edgar Allan Poe wrote "The Narrative of Arthur Gordon Pym in Nantucket" in 1838. It was the story of three starving shipwreck survivors who murder and consume their companion named Richard Parker.
In 1884, three real-life shipwrecked survivors were tried for murdering and eating a fourth sailor named Richard Parker.
-Flammarion, Camille, "The Unknown"

On this date in 1918, Della Sorenson killed her first victim in Nebraska. Her first victim was her sister-in-law's infant daughter, Viola Cooper. Two years later, Wilhelmina Weldam, Sorenson's mother-in-law, was murdered by Della. Della then moved on to her immediate family killing her daughter, Minnie, and her own husband, Joe, during two weeks in September.
Over the next seven years, she continued to kill friends, relatives and even strangers who came into contact with her. She always used poison and liked to poison candy or cookies and give them to young children. Her list of victims and attempted victims include:
 - Viola Cooper - sister-in-law's daughter - dead.
 - Wilhelmina Weldam - mother-in-law - dead
 - Minnie - daughter - dead
 - Joe - husband - dead
 - Clifford - infant son of former sister-in-law - dead
 - Delia - one year old daughter from second husband. - dead
 
She was arrested after trying to poison her new husband and two children from the neighborhood with poisoned cookies. They all survived. She was arrested in 1925. When asked about why she did it, she said "I like to attend funerals. I'm happy when someone is dying." 
She was locked up in a lunatic asylum for the rest of her life.

The supernatural is the natural not yet understood.
Elbert Hubbard

The Bullock Hotel in Deadwood, SD is haunted by the famous sheriff of Deadwood Seth Bullock. He still plays host according to over a hundred stories that have been collected. For more information, check out the link: http://www.historicbullock.com/.