Is there a map for Scarnetti Manor anywhere?
No.
You can get an idea of the outline from the Sandpoint map (in the AP, or from the Paizo map pack) but AFAIK nobody has posted a detailed interior.
Put "manor house floor plan pathfinder" into a google image search and you'll find several suitable floor plans, which could easily be copied and blown up to an appropriate size to be used as a battle map with figures (as I often do).
Come back and tell us which one you chose.