Masha's ghosts that haunt her are the beloved deceased, or else the overwhelming impression on an organic universe of a potent life lived.
Most of the time, I'm too inward to sense emotions outside of me, unless I am aware of a presence to begin with: saints in prayer, God in sacraments, and friends in my home. Once or twice, I've been aware of crossing paths with a demon, and I don't say that braggingly. It's an experience I'd a soon as be happy without. One evening, as I fell into sleep and hovered between the realm of wakefulness and subconscious, a hideous face flashed in my mind. It was twisted and malformed, and yet . . it was the only thing which I could ever describe as having all the appearance and features of a human, without a trace of humanity. I started awake with a whelp. I shivered under my blanket and Hail Mary'd myself back to sleep.
My youngest sister, however, is very intuitive. She's been known to hear the clear sound of a voice, unmistakable speech, at night, outside of a dark house in the un-populated countryside. She is afraid of them, and I don't know whether this is because of her ignorance and innocence or because they are unsavory spirits. But she knows well the strength of the sacraments and the power of the Holy Name, so I've no fear for her.
She watches a reality television show about a medium living in Long Island. The woman is a Catholic and talks about praying her rosary and speaking to Mother Mary, so my sister looked up the Catholic position of her type of spiritualist. A priest instructed that the woman was pure and without blame--if she is able to connect to beings outside of these mortal lives, well, then that is a gift--but he warned that when she made appointments to contact the dead, she went against Church teaching. Deliberately seeking to communicate with the deceased, going so far as to control them through an appointed time of contact, dabbles in a power one should always lay down before the feet of God.
My ghosts are different. They're more like desires. Inverted presences following me around and haunting me and making me miss them. They are absences. Distinct holes of things that are gone from my life, whether it be childhood innocence, harmony with God, joy of purpose, or the longing that is so painful and happy I can only hope to be satisfied in heaven.