From The Glories of Mary by St. Alphonsus Liguori, a continuation of the chapter named Various Examples Appertaining to the Most Blessed Virgin Mary:
4. A woman, who had carried on a criminal intercourse with two young men, one of whom, through jealousy, had killed the other, came one day in great alarm to confession to Father Humphrey d'Anna, of the congregation of the Pii Operarii, in the kingdom of Naples. She told the father that the wretched youth was no sooner dead than he appeared to her, clothed in black, bound in chains, fire issuing from every part of his body, and with a sword in his hand which he had already raised to cut her throat, when she cried out, calling him by his name, 'Ah, what have I done to thee, that thou shouldst take my life?' The damned soul, in a rage, replied, ' What hast thou done to me indeed, wretch that thou art?-----thou hast made me lose my God.' She then called on the Blessed Virgin; and at the sound of the most holy name of Mary, the specter disappeared, and was no more seen.
5. When Saint Dominic was preaching at Carcasone, in France, an Albigensian heretic, who, for having publicly ridiculed the devotion of the Rosary, was possessed by devils, was brought to him. The Saint then obliged the evil spirits to declare, whether the things which he said about the most holy Rosary were true. Howling, they replied, 'Listen, Christians: all that this enemy of ours has said of Mary, and of the most holy Rosary, is true.' They moreover added, 'that they had no power against the servants of Mary; and that many, by invoking in death the name of Mary, were saved, contrary to their deserts.' They concluded, saying: 'We are forced to declare, that no one is lost who perseveres in devotion to Mary and in that of the most holy Rosary, for Mary obtains for those who are sinners true repentance before they die.' Saint Dominic then made the people recite the Rosary; and, O prodigy, at every Hail Mary many evil spirits left the body of the possessed man under the form of red-hot coals; so that, when the Rosary was finished, he was entirely freed. On this occasion many heretics were converted.
6. The daughter of a prince had entered a convent, which was not very fervent, and in consequence, though she was naturally of a good disposition, she advanced but little in virtue. But having by the advice of a good confessor begun to say the Rosary, meditating at the same time on the mysteries, she so changed that she became a model for all. The nuns, however, displeased at her seclusion, did all that they could to make her give up the course she had traced out for herself. One day whilst she was saying the Rosary, and entreating Mary to help her in the persecution she underwent, a letter fell before her. On the outside was written, 'Mary, the Mother of God, to her daughter Johanna, greeting.' Inside it she read: 'My beloved daughter, continue to say my Rosary; avoid intercourse with those who do not help thee to live well; beware of sloth and vanity; banish two superfluous things from thy cell, and I will be thy protectress with God.' The abbot, under whose jurisdiction the monastery was, visited it soon after, and endeavored to reform it, but without success. He one day saw many devils enter the cells of the nuns, but not into that of Johanna; for the Divine Mother, before whom he saw her praying, drove them away. Having afterwards learnt from her the devotion of the Rosary which she practiced, and the letter she had received, he ordered all the nuns to do the same; and the account says that the convent became a paradise.
Keep the Faith!