The Directory for Sunday Celebrations in the Absence of a Priest describes prime alternatives to Sunday Mass:
20. Among the forms of celebration found in liturgical tradition when Mass is not possible, a celebration of the word of God is particularly recommended, (SC 35) and also its completion, when possible, by Eucharistic communion. In this way the faithful can be nourished by both the word of God and the body of Christ. “By hearing the word of God the faithful learn that the marvels it proclaims reach their climax in the paschal mystery, of which the Mass is a sacramental memorial and in which they share by communion.” (Holy Communion and Worship of the Eucharist outside of Mass 26)
The challenge for this, of course, is that ordinary Sunday preaching at Mass doesn’t quite engage the Paschal Mystery. In some communities, it’s a “theme of the week,” based on Jesus’ latest adventure in one of the Gospels at best. Or a moral or political sermon at worst.
Further, in certain circumstances the Sunday celebration can be combined with the celebration of one or more of the sacraments and especially of the sacramentals and in ways that are suited to the needs of each community.
Baptism, I suppose. What other sacramental rite permits a lay person as presider?
Directory for Sunday Celebrations in the absence of a priest English translation © 1988, International Committee on English in the Liturgy, Inc. All Rights Reserved.