What can be done if my husband's social expired but he's been here most of his life?

Although not clear from your question, it sounds like you are a U.S. citizen and you are married to a husband who entered the U.S. lawfully but his visa has expired. If that is correct, then you and your husband may be eligible to file a marriage-based adjustment of status application so that your husband may become a Permanent Resident (to get a "Green Card"). Note that he may be eligible for this notwithstanding that his visa (and Social Security card?) have expired. There are other details too that must be addressed to confirm eligibility, and it would be wise to engage an immigration attorney who, after learning all of the relevant information about your husband and you, could advise about eligibility and represent you in the application process. Some immigration law firms, including mine, offer legal services on a "flat fee" basis so that a client will know the total expense from the very beginning, and a few immigration law firms, including mine, offer an initial consultation free of charge.

A social security number cannot expire. Maybe his EAD card did. You need to meet with an attorney to discuss his options.

A Social Security number never expires. He must have employment authorization status in order to lawfully work in United States. Perhaps, you should have petitioned him, sooner. However, it is unclear whether he can process for a green card in the United States. It will take time and effort before he can lawfully work in the United States as a permanent resident, if possible. I strongly recommend that you hire a competent and experienced immigration attorney to help you with the process. There can be many possible complications where he was unlawfully present in the U. S. It's unclear whether he should file at this time. More information is needed. Good luck.