Do-it.org allows for multiple administrators to share administration of organisation pages with other users or Volunteer Centres.
If you see opportunities or applications from outside of your Volunteer Centre's area, it is very likely that the opportunity is managed by another Volunteer Centre or user. As an administrator of an organisation, you have the ability to view opportunities listed organisations using self service, and you will receive email notifications for all registrations of interest.
Before responding to an out-of-area registration of interest it is important to check which Volunteer Centres are administrators for this organisation so that you do not wrongly deny or accept a volunteer. There is a guide detailing how to check your administrator list for an organisation here.
Another administrator or Volunteer Centre may have added other administrators to the organisation, which could have caused the change. Also, the information for self service users will show in your Recruiter Dashboard.
If you do not believe your organisation or Volunteer Centre has a relationship with the opportunity/registration of interest, you may remove the organisation page from "My Organisations". There is a guide detailing how to do this here.