Camphor makes a space uninhabitable to spirits of lower vibrations (and that includes benevolent ghosts), as well as negative energy. Angelics and higher Divine spirits(beings) can easily still dwell within the space where camphor is burned and kept, but other spirits (even well meaning ones) will be repelled. Camphor can also be used to seal a room against spirit presences by first cleansing a room, and then placing chunks of camphor resin in each of the room's corners.

4 Camphor Tablets