Ringtail possums. So cute. We often see them on our phone and power lines at night.
Luckily we don't have any possums inside the house or roof any more. We used to have a couple of resident brushtail possums living in the wall cavities (they even chewed holes right through the weatherboard for ventilation).
Paul the Possum Catcher took care of that years ago with his humane one-way exit system, and we haven't had a problem since. They still visit and eat the fruit in our garden. But we don't mind sharing :)