O Blessed Saint Joseph, faithful guardian and protector of virgins, to whom God entrusted Jesus and Mary, I implore you by the love which you did bear them, to preserve me from every defilement of soul and body, that I may always serve them in holiness and purity of love. Amen.
Further reading
For a sustained devotion to St. Joseph, Donald H. Calloway offers a 33-day consecration program with reflections and prayers about his fatherly care and protection.