In the text of the Apocalypse 12 7 9 Saint Michael Archangel is named. In the town of Skala where the port is located on the road that is cross the town to go to the cave of Apocalypse there is a small private church dedicated to Saint Michael Archangel.
Its usually open and is possible to go inside to pray and light a candle.
The island of Patmos is located on the St. Michael line that start in Ireland and end in the Holy Land where you can find monasteries and churches dedicated to St. Michael.