[Gracie2006]

I would first verify that it is indeed your dog. It seems strange that she would suddenly start barking. Can you set up a voice recorder next to her pen? You can buy MP3 recorders fairly cheap that record for long periods. If it is your dog, I found online a barking collar for small dogs that you could try. If interested, I can try and find the link. In the interim, I would speak with the person who sent you the note, if you know who it is, and explain that you think they may have the wrong apartment but that you are investigating things from your end.