Firstly, there are no souls of the dead present. Even in his own Catholic theology, the dead are not wandering around willy nilly, and being a priest, he aught to know that.
Secondly, he is doing more than praying to them. First, he is “detecting” their presence, by his feelings, which means he seeking out contact with them. Otherwise, he would be dismissing those subjective feelings or praying to God to remove them from him, not indulging in them.
Third, besides simply seeking out these spirits, he attempts to communicate with them, as demonstrated by this:
“The priest has found an effective formula is to have a Mass said for any soul that seems to be disturbing a place and gently telling the soul, “Call to Jesus. Keep saying ‘Jesus’ over and over, until He comes.””
See that? He is “telling the soul” something, so he is communing with them.
He is offering prayers for the repose for that person’s soul.