2006 Ford Expedition -Tinks in back

Guys,
When using AC in rear of car, there is a tinking noise from the right rear interior compartment above/ahead of rhe wheel well. What is it and can i fix it?
Thank you.
P.S. I listen, via podcast, every week. Love it!

It is likely something touching the blower motor for the rear AC. Take it apart and find the culprit and remove it. easily said… not so easily done!