So that works then, which is good, now you have to stop it and others from coming back, and that’s what having great spiritual hygiene and wards are for. The first makes you invisible or unattractive to parasites, the second puts up a barrier around your house/self/work they can’t cross. An ounce of prevention and all that 
Third link down has a form of warding. I generally draw a protective circle around my who house using a little house salt and the ash from my censer. I also have up old fashioned iron horseshoes and a railroad spike under my bed.