The Holy Spirit is active even outside the visible confines of the Catholic Church.
John 3:8 says, “The Spirit breatheth where he will and thou hearest his voice: but thou knowest not whence he cometh and whither he goeth. So is every one that is born of the Spirit.” (Douay-Rheims)
We should rejoice in the work of the Spirit even when it is outside the visible Church.
Mark 9:38-40 says, “John said to him, ‘Teacher, we saw a man casting out demons in your name, and we forbade him, because he was not following us.’ But Jesus said, ‘Do not forbid him; for no one who does a mighty work in my name will be able soon after to speak evil of me. For he that is not against us is for us.’”
The Catechism of the Catholic Church touches upon the work of the Holy Spirit outside the visible Church:
818. “However, one cannot charge with the sin of the separation those who at present are born into these communities [that resulted from such separation] and in them are brought up in the faith of Christ, and the Catholic Church accepts them with respect and affection as brothers…All who have been justified by faith in Baptism are incorporated into Christ; they therefore have a right to be called Christians, and with good reason are accepted as brothers in the Lord by the children of the Catholic Church.”
819. "Furthermore, many elements of sanctification and of truth" are found outside the visible confines of the Catholic Church: “the written Word of God; the life of grace; faith, hope, and charity, with the other interior gifts of the Holy Spirit, as well as visible elements.” Christ’s Spirit uses these Churches and ecclesial communities as means of salvation, whose power derives from the fullness of grace and truth that Christ has entrusted to the Catholic Church. All these blessings come from Christ and lead to him, and are in themselves calls to “Catholic unity.”