Jackson Electric Membership Corp. will be mailing $5 million in refunds to 180,000 members who received service in 1988 and 2011.The decision was announced by the Board of Directors on Thursday at Jackson EMC’s annual meeting. Checks will go out in December. How much a customer receives depends on the electricity used, Jackson EMC spokeswoman Bonnie Jones said.“Because we are a not-for-profit cooperative, the Board of Directors is able to return a portion of the revenue left over after all the bills are paid, funds which we refer to as ‘margins’, to our members at the end of each year,” board Chairman Otis Jones said.