Just a thought on the subject, bearing in mind that some of mine go ALL
over the floor, and I have tried it all?
 
Put your ferret in a smaller cage for a while to remind him of his
manners.  Make sure he has plenty of hours of play time with you out ot
the cage.  This HAS worked for me.
 
(You should have a time out cage, and/or a sick cage and/or a smaller
cage to grab in case of a fire or flood: one that fits in your car.)
 
Pour rubbing alcohol on the board he pooped on, and rub it in, and allow
it to thoroughly dry.  That will end the pooping on the board.
 
Get a new litter box.  Maybe a chemical or smell is in there that
persuades him to go elsewhere.  Make sure you change the litter entirely.
When mine poop elsewhere, it can mean -for the "good poopers"-- that all
the old litter must be dumped and the box thoroughly cleaned with
disinfectant..
 
From your pooping expert
who stepped in 2 piles last night trying to avoid 5 others in the dark as
she walked in the door while carrying 2 heavy bags, surrounded by leaping
poop contributors;
 
Lisette and her diss-funk-channel family
[Posted in FML issue 3919]