Miracles Versus Work of the Devil

Four days after Pope John XXIII died, his apparition reportedly appeared to Sister Caterina Capitani, a nun of the Sisters of Charity of St. Vincent de Paul who had been suffering from severe gastric hemorrhages, a condition thought to be incurable.  She had just had unsuccessful surgery for the condition and was in a hospital in Naples preparing to die when she felt a hand upon the incision which had opened on her abdomen.  She turned to see the spirit of the late pope who said to her, "Sister, you have called to me  so many times, as have so many of the Sisters of Charity of St. Vincent de Paul, that you have turned torn out of my heart this miracle. But now do not fear. You are healed!"  The moment the spirit of the deceased pope diasappeared, Sister Capitani was able to rise from her bed and reported no pain.  The open wound on her abdomen was gone.  Not even a surgical scar remained.  The event was deemed a miracle in May 1966.  Among Christians, the act is often deemed a miracle.  However, whenever similar phenomena occur among members of other spiritual groups, orthodox clergy are likely to denounce the "miracle" as the work of the devil. Is a reported healing by an intervening ghost or spirit entity any less valid than a miraculous act performed by a religious figure or saint?