Things to avoid include Elizabethan ghosts, Roman soldiers, Viking ghosts, Celts etc. If you really want to use these, you'll need to change your setting or else come up with a way to transplant them believably to Australia. Then there are animal ghosts. A haunting hound works just as well in Write Australia as in Victorian England. A spooky kangaroo somehow doesn't quite cut it.
Haunted settings abound in Australia, just as in any other country.
Since this article is about supernatural danger, we need to concentrate on ghosts that might mean or cause harm. Most of the above spooks could bring danger to your living characters, either deliberately or simply by their presence. That violent miner ghost might not really intend to harm Ben. From its own viewpoint it might be threatening a murderous contemporary. This points to yet another fork in the decisions road.