Try Pollokoo and Callopee. Though not on the wiki, there are a bunch of ghosts in these regions.
Pollokoo :
Quluuwaa Luwa http://lem.to/p/YNJN
Kikal Kalzo http://lem.to/p/DyD9
Sambossa Bossa http://lem.to/p/0AZj
Kotteletti Kota http://lem.to/p/MSsW
Callopee :
Yebeg Yobs http://lem.to/p/vlCy
Paodoo Lets http://lem.to/p/4da3
Vekke Vets http://lem.to/p/C7uq
Keywot Whot http://lem.to/p/ijpp
EDIT: I just added these to the wiki page