Background check for The Red Cross.

Has anyone had a background check on the spot? I will be volunteering for the Red Cross. They need bilingual interpreters. They will take a background test 15 minutes before orientation. My S.S# appears on the self check website. Im wondering will I need my s.s number or just my name DOB and such? I've never had a background check on the spot so Im just wondering if anyone has gone through and passed it.