Involvement with Santa Muerte is spiritually dangerous and it is not Catholic in any way. It should be completely avoided. It is a perversion of devotion to the saints.
In 2013, Cardinal Gianfranco Ravasi, the President of the Vatican's Pontifical Council for Culture, denounced the Santa Muerte practice as "sinister and infernal." He called it a "blasphemy of religion."
The cult of Santa Muerte has been linked to violent drug cartels and brutal ritual killings. While it is popular in Mexican prisons, it has followers in many walks of life in Mexico and in some parts of the United States. The principal sanctuary of Santa Muerte is in Tepito, Mexico City.
We must distinguish true saints from false saints and superstitions. Authentic saints are those found in the Bible and those who have passed through the official process of beatification and canonization by the Vatican. Santa Muerte is not one of them.
Rather than asking Santa Muerte for protection or favors, we should turn our life over to Jesus Christ, repent of our sins, make a sincere Confession, follow God's commandments, and trust in the grace of God. Catholics and other Christians should get rid of any Santa Muerte statues, candles, or other paraphernalia.
In his Resurrection, Jesus Christ conquered death. Through our Christian Baptism, we share in his victory.