It is Nigerians trying a variety of things to scam people. They call from Florida & Texas numbers,  may try to text with you & they have heavy accents.
One guy whose number is 832-478-7411 and whose alias is "Mr. Martin Walls" somehow preys on websites (like Trovit) listing rental properties & tries to get interested people to send him money by pretending to be the property owner who has transferred out of town & just needs a good tenant. He provides a Nigerian address for his prey to send money via Moneygram to his lawyer visiting West Africa on vacation. Most of the rentals are already occupied by unsuspecting people with no idea their home is attempting to be rent out to others.
They can be very accommodating & very aggressive.
Alert your local police if you fall victim or almost do...maybe enough police reports can shut them down.