Can you please share the prayer with us?
Thanks
St. Michael the Archangel, defend us in battle.
Be thou our defense against the wickedness and snares of the Devil.
May God rebuke him, we humbly pray,
and do thou, O Prince of the heavenly hosts,
by the power of God thrust into hell Satan,
and all the evil spirits who prowl about the world
seeking the ruin of souls.
Amen.
There is also a second part which is not generally recited after Mass:
O glorious prince St. Michael, chief and commander of the heavenly hosts,
guardian of souls, vanquisher of rebel spirits,
servant in the house of the Divine King, and our admirable conductor,
you who shine with excellence and superhuman virtue
deliver us from all evil who turn to you with confidence,
and enable us by your gracious protection
to serve God more and more faithfully every day.
Amen.
If I recall correctly, this was originally promulgated by St. Pius X.
Oratio ad Sanctum Michael
This is a very helpful website with a collection of prayers in Latin and with translation.
Prayer to St. Michael the Archangel
St. Michael the Archangel,
defend us in battle.
Be our defense against the wickedness and snares of the Devil.
May God rebuke him, we humbly pray,
and do thou,
O Prince of the heavenly hosts,
by the power of God,
thrust into hell Satan,
and all the evil spirits,
who prowl about the world
seeking the ruin of souls. Amen.