This is an excerpt from a 1978 document by the Congregation for the Doctrine of the Faith, on “Criteria for Discerning Apparitions and Revelations”: I’m copying it from a web page at mariedenazareth.com
I. Criteria of judgement, concerning the probability of the character of the apparitions and supposed revelations.

  • A) Positive criteria:
    • a) Moral certainty, or at least great probability, as to the existence of the fact, [revelation] acquired at the end of a serious investigation.
    • b) Particular circumstances relating to the existence and the nature of the fact:
      • 1. Personal qualities of the seer–in particular mental balance, honesty and rectitude of moral life, habitual sincerity and docility towards ecclesiastical authority, ability to return to a normal manner of a life of faith, etc.
      • 2. With regard to the revelations, their conformity with theological doctrines and their spiritual veracity, their exemption from all error.
      • 3. A healthy devotion and spiritual fruits which endure (in particular, the spirit of prayer, conversions, signs of charity, etc).
  • B) Negative criteria:
    • a)A glaring error as to the facts.
    • b) Doctrinal errors that one would attribute to God himself, or to the Blessed Virgin Mary, or the Holy Spirit in their manifestations (taking into account, however, the possibility that the seer may add something by their own activity–even if this is done unconsciously–of some purely human elements to an authentic supernatural revelation, these having nevertheless to remain free from any error in the natural order. Cf. St Ignatius, Spiritual Exercises, n. 336).
    • c) An obvious pursuit of monetary gain in relation with the fact.
    • d) Gravely immoral acts committed by the seer, or his associates, at the time of the facts, or on the occasion of these facts.
    • e) Psychic disorders or psychopathic tendencies concerning the seer, which would exert an unquestionable influence on the allegedly supernatural facts, or indeed psychosis, mass hysteria, or other factors of the same kind.

It is important to consider these criteria, whether they are positive or negative, as indicative standards and not as final arguments, and to study them in their plurality and in relation with the other criteria.
[…]
III. Other Authorities Entitled to Intervene

  • 1. The foremost authority to inquire and to intervene belongs to the local Ordinary.
  • 2. But the regional or national Episcopal Conference may intervene.
  • a) If the local Ordinary, after having fulfilled the obligations which fall to him, resorts to them for a study of the event in its entirety.
  • b) If the event assumes national or regional importance.
  • 3. The Apostolic See can intervene, either at the request of Ordinary himself, or at the request of a qualified group of the faithful, or directly by virtue of the immediate right of universal jurisdiction of the Sovereign Pontiff (cf. above, IV).