WASHINGTON — The top Republican on the Senate Finance Committee has launched a wide-ranging investigation into the financial dealings of six TV evangelists, including Joyce Meyer, the popular preacher who has built a $124-million-a-year empire headquartered in Fenton. On Monday, Sen. Charles Grassley, R-Iowa, asked Meyer to provide his staff with documents detailing the finances of the Joyce Meyer Ministries, including the religious group's compensation to Meyer, her husband and other family members, as well as an accounting of their housing allowances, gifts and credit card statements for the last several years.