The following items are all dangerous to some degree if ingested, or placed in contact with your ferret. Some can cause death almost instantly. Others may cause only a mild reaction, but it is best to remove them from any areas where they would be in contact with your ferret.
This is not a complete list, so if you are in any doubt about something that your ferret has eaten or been in contact with, please contact your veterinarian or the National Animal Poison Control Center at (888) 426-4435. (They charge $65.00 per case.)