A question has been raised that has not been banned from being debated on this board, and that is, does canon law allow for a Catholic to take part in a valid but illicit Mass? The answer is yes, but only under exceptional circumstances, and even then, Canon law allows only taking part in the Liturgy of the Word, and not receiving communion in illicit Masses.
intratext.com/IXT/ENG0017/_P4L.HTM]Can. 1248
§1 The obligation of assisting at Mass is satisfied wherever Mass is celebrated in a catholic rite either on a holyday itself or on the evening of the previous day.
§2 If it is impossible to assist at a eucharistic celebration, either because no sacred minister is available or for some other grave reason, the faithful are strongly recommended to take part in a liturgy of the Word, if there be such in the parish church or some other sacred place, which is celebrated in accordance with the provisions laid down by the diocesan Bishop; or to spend an appropriate time in prayer, whether personally or as a family or, as occasion presents, in a group of families.
A Catholic cannot attend illicit Masses if there are licit Masses available. All SSPX Masses are illicit. It is a sin for a Catholic to attend an SSPX Masses if there are licit Masses available, and it is an even greater sin to receive communion in an SSPX Mass, since the SSPX is in schism with the Catholic Church.
The SSPX is a Protestant denomination.