Will? Yes or No? Is there an estate that needs to be probated....probate assets?
Funeral home directors always get Obits published.....someone should be in touch even if it's a distant cousin.
A will can be filed for probate. Notice will be published. If no one shows up the court can appoint anyone it its discretion. If you're not interested you can take the will...if any....to a local lawyer.
Question is regarding what options exist for finding and appointing/naming an executor for a will when no standard alternative (e.g. family member) exists. No one is dead yet...just trying to get some paperwork in place for that eventuality :--)
Answer is there are professional executors that can be used as a fallback. Banks, accountants, financial advisory firms, and the like will all do it for a fee of course but it's standard to use a 'corporate' fiduciary as a fallback in case it ends up being that there is no one else living at the time.