My Aunt in Ohio passed last year . She had no Executor for her estate. Her son left 7yrs ago & hasn't been seen since. I cremated her body . Next step

You can file for probate of her Will and to be appointed executor in probate court in Ohio.  Her son will need to be notified, so you will have to try to find him.  The necessary forms are available from the probate court for the county where your aunt lived.