A picture of Michael the Archangel placed over the door of your home will help keep troublesome spirits and those who would harm you away. When you place the image, you should say the St Michael Prayer:
"St Michael the Archangel, defend us in battle. Be our protection against wickedness and snares of the devil. May God rebuke him we humbly pray, and do thou, O Prince of the Heavenly Host, thrust into hell Satan and all other evil spirits who wander the world seeking the ruin and destruction of souls. Amen."
This will work for you even if you are not Judeo-Christian or Catholic.
HOWEVER, this is not a cure against common sense. ;) Obviously, if someone is threatening you or trying to physically harm you, you need to call emergency services and/or police services.