Who needs a vulnerable sector check?

It depends on the position, not the person. The RCMP says the nature of the position must give the person authority over, or trust of, children or vulnerable persons. Children means anyone under 18; vulnerable persons are people who, because of their age, disability or other circumstance, are more vulnerable than others. The hiring or volunteer organization decides whether to request a check, and the applicant gives consent but does not make the request.

Source: https://rcmp.ca/en/criminal-records/criminal-record-checks/vulnerable-sector-checks