If you ever find yourself in a situation where one person has multiple profiles, here’s what you can do.
Step 1: Remove the duplicate profile from your organization. Note that this will remove data from the profile, so you might want to copy (manually) any data from that profile into the one that will be kept.
Step 2: Have the volunteer merge their profiles. This is something that only the volunteer can do, since they may be using that profile to volunteer with another organization.