Is there a ninth fold to the Eightfold path or is it just eight?
There is the:


8 Fold Path is the practice up to Sotapanna, and
10 Fold Path for full enlightenment


The Noble 8 Fold Path is the practice up to Sotapanna.



Source: Maha Cattarīsaka Sutta intorduction

To go beyond Sotapanna one must add 2 more elements under liberation/release which are:


right knowledge
right freedom




Maha Cattarīsaka Sutta