Michael McGuire was a man who Carmel Finnan became obsessed with.
Michael and his wife lived the neighbouring farm to the one where Carmel's grandparents resided. Aged fourteen, Carmel discovered the truth about her grandparents (who had raised her as their daughter after her mother became pregnant out of wedlock at the age of fifteen) and took up with the McGuires and lived on their farm. However, she eventually soured her relationship with the family after accusing Michael of being the father to her non-existent child. After finding out about her actions, her grandparents placed her in a hospital which she left after a year apparently a fine, cheerful woman who had put her dark past behind her and expressed the desire to take up nursing.
Arriving in England, Carmel once again grew an obsession with another man - Martin Platt, also pretending that he was the father of her non-existent baby. Eventually, Carmel's secrets were found out when her grandfather John Finnan arrived in Weatherfield to question the Platts and noticed the similarities to Carmel's obsession with Michael, he apologised to the Platts and told them that he would take Carmel home to Ireland to get the care she needed.