Pennsylvania is a beautiful state with rolling hills, family farms, and beautiful forests. Hidden among this beauty you will discover a different side of PA, full of wonderful folk tales as well as numerous ghost stories and haunted places.  As always use common sense and courtesy when visiting.  By no means is this a complete list of haunted places within PA.

The State Theatre, (Easton)  The resident ghost is named Fred.  Some believe him to be the ghost of a former manager of the theatre.
Rexmont Inn, (Rexmont)  Haunted by the ghost of the niece of the man who originally built the place.  It was a private residence before being turned into a bed and breakfast.
Temperance House, (Newtown)  Haunted by the spirits of two colonial children.
The King George II Inn, (Bristol)  This is the oldest continually operating inn in the USA.  Haunted by the ghost of a man wearing a top hat and tails.  (FYI--remember the 60's song "Bristol Stomp" by the Dovells--that's right, the Bristol Stomp's birthplace was Bristol PA!!)
The Logan Inn ( New Hope)  Haunted by a variety of ghosts, including the ghost of a little boy, a fully uniformed Revolutionary Soldier and even Aaron Burr. (FYI--it is said the almost everything in New Hope is haunted!!)
The Jean Bonnet (Shellsburg) haunted by several ghosts including a little boy.
Jim Thorpe Jail (Jim Thorpe)  the handprint of a man name Tom Fischer is still on the wall of his cell.  Tom was hanged because it was believed he was a member of the Molly Maquires and had taken part in a murder.  He insisted clear up till the time he was hanged that he was innocent.  He left his hand print on the wall in Cell #8 as a way to remind the world that they hanged an innocent man.  (as with many ghost stories handed down throughout the years,  different versions of this story exist, go here to read more.)
The INN Philadelphia (Philadelphia)  Haunted by a ghost who likes to pull hair.
Covatta's Brighton Lodge (Douglasville) Haunted by a variety of ghosts, one called "the Bride" the other called "Dapper Dan".
Baker's Mansion (Altoona)  A dress that is locked in a glass case has been seen moving.  Also spotted at times, is a woman in black.
The General Wayne Inn (Merion)  Possibly haunted by the ghost of Edgar Allen Poe.  It is believed that Poe wrote part of  "The Raven" while on one of his visits in 1843.  The ghost of a Hessian soldier is sometimes seen as is the ghost of a young British officer, who sometimes asks those who have encountered him, if he can have his locket back.
Fulton Opera House (Lancaster)  The sounds of phantom applause has been heard.  Also, the piano plays by itself at times.  A figure dressed in 19th century clothing is sometimes seen.  A variety of other spirits, one perhaps being that of Sarah Bernhardt, who performed at the theatre in 1912.  Also, silent film star Marie Cahill's  spirit may also be present in the theatre.
Easton Public Library (Easton)  The library sits on what was once a cemetery.  Strange noises, things moved, doors opening on their own and other various happenings await you.
The Inn At Maple Grove (Albertis)  When you're there,  make sure to say  hello to "Charlie" the resident mischief maker.
Widow Brown's Inn (Stockertown) Sit down and have a meal and keep your eyes open for "Marvin", the resident ghost.  Marvin is rumored to be the ghost of a man who hung himself in the back stairway of the restaurant. (FYI--the sister restaurant in Wescoville also has a resident ghost).
Moshulu (Philadelphia). She was once a fully rigged, working ship that sailed the high sees from 1904-1940.   During her 36 years as a working ship, twenty-eight sailors in all lost their lives.  Now, the Moshulu is a floating restaurant.   While you are enjoying your dining experience, you might hear strange noises, or perhaps witness a lantern igniting on its own. Are these the antics of sailors long since dead?
The Gettysburg Battlefield: Places like the Triangular Field, Spangler's Springs, Little Round Top have their share of ghosts.  Many places in Gettysburg, not just the battlefield itself have ghost stories associated with them. There is a ghost tour offered, so if you get the chance, check it out. 
Valley Forge:  While no battle was fought here, it is estimated that as many as 3,000 to 4,000 soldiers died from disease and exposure during the harsh winter of 1777-78.  Ghosts of Colonial soldiers have been seen wandering near the huts.  Some say that George Washington's spirit  can still be felt and is at its strongest at the stone house that was used as his headquarters.
Betsy Ross House (239 Arch Street, Philadelphia).  It is thought that Betsy is the ghost who  is heard crying at the foot of what was once her bed.   Some believe that Betsy never lived at this house, others aren't so sure.  Strange sounds are also heard coming from the basement of the house and there are those who attribute this noise to the ghost of  the founder of  Betsy Ross Memorial Association.  Others think it might be the ghost of a former employee of the gift shop who was killed in the basement.
Independence Hall (3rd and Chestnut Street, Philadelphia) The clock tower is believed to be haunted.  And, a ghost dressed in 18th century clothing has been spotted on several occasions.
Carpenters Hall (320 Chestnut Street, Philadelphia)  Odd sounds and smells greet visitors at times who come to this historic building.  Also seen are footprints in the dust on the floors, footprints that aren't made by any living person.  As a side note here, the nations first bank robbery occurred here on September 1, 1798.  Two men walked into the Bank of Pennsylvania which was located, then, on the first floor of Carpenters Hall and made their demand for money.  It is was believed that the robbery was an inside job and  that one of the robbers was a gent who lived on the third floor of Carpenters Hall.  He was arrested but released a few days later.  (Several years later ,it is reported that. he died after contracting yellow fever)  Is it his footprints that are sometimes seen in the dust that settles on the floor?
Fort Mifflin (Fort Mifflin Road, Philadelphia)  The ghost of a young Continental soldier has been seen.  During the Civil War, this fort also was used to house Confederate prisoners of war, it seems some soldiers are still there….
Eastern State Penitentiary (2125 Fairmount Avenue, Philadelphia)  This was the nations first penitentiary.  Former guards as well as former prisoners have been seen.   In the 1800's this prison was a role model for other prisons.  The idea pushed here was to keep prisoners in solitary confinement so they could ponder and become "penitent" for their wrong doings.  Many prisoners went mad from being kept in solitary confinement.  ( please note that it is best to call ahead to find out when tours of this place are being given)
Cornwall Iron Furnace:  (Rexmont Road and Boyd Street, Cornwall) Legend has it that at one time, while out hunting, the ironmaster of the furnace became so enraged at his pack of hunting dogs for not being able to scent their prey that he took the dogs back home and threw them, one by one into the furnace, burning them alive.  On some calm, quiet nights, the sounds of dogs barking can be heard coming from the furnace area.  Also, rest assured that the ironmasters cruelty was not forgotten, he slowly sank into a depression after this event and as he lay on his death bed, he complained of hearing the sound of barking dogs---the very ones that he was responsible for killing?
Pearl S. Buck House  Although she was born in West Virginia and spent most of her childhood in China, it was in Bucks County, Pa, where Pearl spent about half of her life.   Pearl wrote most of her short stories and other books at her farm (Green Hills Farm) in Bucks County.   Many people say that there is "something" there at the farm.  Pearl herself was delighted to learn that there was a ghost associated with her home and wrote about "Devil Harry" in her book "My Several Worlds" .  Devil Harry is a ghost who takes a  stroll on the farm every Christmas Eve at midnight .  Pearl died in 1973  and is buried at the farm which has since been turned into a historical site.   While no one has ever admitted to seeing her as a ghost, they have seen other spirits.  Staff members have seen a woman dressed in Colonial garb walking through one of the bedrooms.