St. Michael has appeared in apparitions more than any other angel – he has visited many Saints, but his most notable shrines are at Monte Gargano in Italy and Monte Michel in Normandy – I should point out that others have attributed some of these events to other angels - 
SAINT MICHAEL SHRINE - Gargano, Italy
In Apulia, on Monte Gargano, the town of Monte Sant’Angelo contains the most famous shrine of the Latin West dedicated to the Archangel Saint Michael. Placed on top of the mountain this singular Basilica made up of a complex of constructions around the grotto from various eras, gives evidence of a good fifteen centuries of history. From remote times this is a place of pardon and prayer, famous in the entire Christian world. An anonymous writer, who lived more than a thousand years ago, describes it thus:
“The shrine of Saint Michael is known and extolled everywhere not for the splendour of its marble, but for the prodigious events that took palce here; of modest form, it is nevertheless, rich in celestial virtue, because the Archangel Michael himself deigned to set up and consecrate it, who being mindful of human frailty, came down from heaven so that men could participate in things divine in that temple”.
VIRTUAL VISIT
Mother Angelica claimed to have a vision of St. Michael. I believe her account.
In 1993, EWTN launched WEWN, a shortwave radio station, the world’s largest privately owned facility of its kind. The money came from the late Piet Derksen, a Dutch leisure-industry billionaire who had never met Mother Angelica until he spotted her in a hotel lobby in Rome. Ask her how she came to start the shortwave operation, and she’ll tell you it was the archangel Michael—literally. She saw him on a hilltop near Irondale, and he told her to build it there. So she did, even though experts told her it wasn’t an ideal location.Mother Angelica's Empire of the Airwaves
And this:
She is reflecting on the 20th anniversary of EWTN—a "miracle," as she calls it—but also on the shrine itself, another miracle. "I think it is going to give people courage. They lack awe—of the real presence of Jesus in the Eucharist. And they lack courage—they won’t fight for anything. They have no guts. I think what they experience when they walk into the church is courage. That’s why it was built."
Mother Angelica gives me courage. No challenge I face comes close to the number or magnitude of challenges that she faced --willingly.