How do you clear it? i dont see the evil spirit anywhere in the location on the wiki, location 31 on the map.

i have so much other questions i just post them here 

There is a building in Calterburry in the bottom right with two guards standing in front of the entrance. The entrance is "below the npcs"  out of vision so I assume you didn't realize there is one. Once you have the quest you can talk to the guards to get in.