Can an employer take part of your earnings and add to it and call it Fringe Benefit to pay for health coverage for a salary employee.

If you are saying that the employer reducted or deducted the salary to pay for health insurance, then this would be a salary basis violation and a breach of contract.  Can an employer lower a person's salary?  yes, but they cannot just simply take the money just to pay for the health insurance.  Also, this may be a salary basis violation which then makes any such employee eligible to obtain a premium for overtime hours.  Consult a lawyer experienced in FLSA.  you can also contact me if you need further legal advice.