I had some live catch ferret traps made to my own design because I could never find anything that fitted the bill perfectly.
The end result was something that looks very similar to a mink trap but it?s made from wood to keep a captured ferret warm overnight once caught.
I place the trap facing the hole in the burrow, which I last knew the ferret to have used.
I then block all the other holes so that the ferret has no other choice but to use the exit near the trap.
I also scatter traps in the general area just in case the ferret had vacated the area via a hole I might have missed.
A mink trap will do but you will need to wrap it in cloth or sacking because a low night-time temperature could kill the ferret if captured.
By all means place some hay or straw inside the trap but just make sure it doesn’t interfere with the mechanism.
In spite of this I still think it best and safer to copy the mink cage in wood.