Time Slips and Premonitions in New Jersey

Time slips and premonitions in New Jersey. My grandmother had a lot of unusual experiences of her own. Once as a young child she peaked out the window of her little family home on a dark winter night to see an old woman that she could only describe as a witch looking in at her. At another time as a teenager she and some friends went snooping around an empty house that had a piano left in it. One that she had never heard before or since. It wasn't a player piano so there were no explanations for how it was being played.