When Paul wrote to the Galatians, he was correcting an error. The Galatians had been deceived into adding Jewish rituals into their church.
Paul told them they had been bewitched.
Witchcraft is often associated in scripture with necromancy and communication with the dead. Saul sought out a witch to bring up Samuel.
Adding any law to the message of grace, whether man-made or bringing back the Mosaic law, is to be bewitched. It is trying to use something that is dead to live your life.
Paul told the Galatians to Stand fast in their liberty, and not to return to the deadness of laws and ordinances.