Call Social Security. They will be able to mail you out a new card.
Social Security does not mail out cards by phone. You must go into the office with verification documents and you will receive the card in the mail in about 10 days. You can get the list from ssa.gov
For a childs card it's a birth certificate and all kinds of stuff, call before going, preferably the day before @ around 9. Check the times to come in. An hour after open is good.
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