This regex targets a customer specific requirement for a regex that matches US Social security numbers either separated by -(dash), space or nothing.

So it should match: 702-02-9921 702 02 9921 702029921

As it may be dangerous to have a regex that matches a sequence of 9 number I made it very strict to reduce the amount of false positives

So it should not match: Telephones, credit cards, same number sequences, 0 sequences, numbers starting with 9, mixed space and dashes

Inspired by: https://www.codeproject.com/Articles/651609/Validating-Social-Security-Numbers-through-Regular