The Church gives us parameters as to what can and cannot take place within the framework of the Holy Sacrifice of the Mass. The General Instruction of the Roman Missal states that:
65. The homily is part of the Liturgy and is strongly recommended,63 for it is necessary for the nurturing of the Christian life. It should be an exposition of some aspect of the readings from Sacred Scripture or of another text from the Ordinary or from the Proper of the Mass of the day and should take into account both the mystery being celebrated and the particular needs of the listeners.64
66. The Homily should ordinarily be given by the priest celebrant himself. He may entrust it to a concelebrating priest or occasionally, according to circumstances, to the deacon, but never to a lay person.65 In particular cases and for a just cause, the homily may even be given by a Bishop or a priest who is present at the celebration but cannot concelebrate.
There is to be a homily on Sundays and holy days of obligation at all Masses that are celebrated with the participation of a congregation; it may not be omitted without a serious reason. It is recommended on other days, especially on the weekdays of Advent, Lent, and the Easter Season, as well as on other festive days and occasions when the people come to church in greater numbers.66
From Redemptionis Sacramentum we see that:
[64.] The homily, which is given in the course of the celebration of Holy Mass and is a part of the Liturgy itself,142 "should ordinarily be given by the Priest celebrant himself. He may entrust it to a concelebrating Priest or occasionally, according to circumstances, to a Deacon, but never to a layperson.143 In particular cases and for a just cause, the homily may even be given by a Bishop or a Priest who is present at the celebration but cannot concelebrate".144
[65.] It should be borne in mind that any previous norm that may have admitted non-ordained faithful to give the homily during the Eucharistic celebration is to be considered abrogated by the norm of canon 767 §1.145 This practice is reprobated, so that it cannot be permitted to attain the force of custom.
[66.] The prohibition of the admission of laypersons to preach within the Mass applies also to seminarians, students of theological disciplines, and those who have assumed the function of those known as "pastoral assistants"; nor is there to be any exception for any other kind of layperson, or group, or community, or association.146
Some could make the argument that such a skit or play could occur after the post-Communion prayer. However, according to Redemptionis Sacramentum:
[161.] As was already noted above, the homily on account of its importance and its nature is reserved to the Priest or Deacon during Mass.260 As regards other forms of preaching, if necessity demands it in particular circumstances, or if usefulness suggests it in special cases, lay members of Christ's faithful may be allowed to preach in a church or in an oratory outside Mass in accordance with the norm of law.261 This may be done only on account of a scarcity of sacred ministers in certain places, in order to meet the need, and it may not be transformed from an exceptional measure into an ordinary practice, nor may it be understood as an authentic form of the advancement of the laity.262 All must remember besides that the faculty for giving such permission belongs to the local Ordinary, and this as regards individual instances; this permission is not the competence of anyone else, even if they are Priests or Deacons.
While a skit is not necessarily lay preaching, it is something of an anamoly that really has no place in the Holy Sacrifice of the Mass. When we gather for the Mass, we are engaging in a sacred, holy act. We are participating in the Church's greatest prayer. A skit, as well-intentioned and as well-performed as it is, belongs outside of the realm of the Holy Sacrifice, in the parish hall.