“Grandparent Scams” are often carried out over the phone by people claiming to be a relative of the victim, usually a grandchild, who claims to be in trouble and in need of money immediately. Also, beware of people calling to ask for payment with a prepaid card, utilities and businesses will not contact customers seeking payment with a prepaid card.
https://www.wcia.com/news/illinois-police-issue-warning-of-scam-targeting-seniors/