The spirit realm and the physical realm exist on this earth, but in different dimensions. The spirit realm may often overlap our physical realm, bringing the two as one. Other times, we hear noises coming from the spirit realm, but heard in the physical realm. This is why a person hears boxes being knocked over in their basement, but no boxes are out of place. The boxes being knocked over existed in the spirit realm, but was manifesting the sounds in the physical realm.
Ghosts love to be pranksters.
They love a good joke. They love humor. If you will examine your ghostly experiences, you will find the pranks were simply harmless pranks that scared the boo-boo out of you because you fear the unknown. Once you come to an understanding of life after death and that ghosts are the evidence of life after death, our fears slowly fade away. Some are here because they want to be, others are anchored here because of unfinished business or unresolved issues.