Answer: A spark of good, God or whatever you wish to call it, lives in your heart and radiates from your heart. This goodness or light radiates from your within. It alone is your protection. Darkness can not exist where there is light and you have light already within your inner being. The trouble is that unless you acknowledge this light and truly believe in its existence you will in a sense be open to the dark light because that is what you believe. By believing it, it is so. By believing that your light is sufficient protection, it is so. By using techniques such as building white light around you, it is so. Whatever method works for you and if you believe in it, it is so.
HOWEVER, are all your techniques, methods and rituals really necessary when all along the spark of God is with you and within you in any case. Once you have grasped this truism, then you need not worry about darkness for darkness will not be attracted by you. Like attracts like. Your light can only attract light!
This does not mean that you must ignore a respectful process if you are working in the area of rescue work, house blessings and possession cases. For you have links to others who may not have the same trust in their own inner light as you and therefore all these links must be guarded and protected. This can be done by using your own light that shines from within to radiate out to all these boarder links. But, this is another subject and therefore requires a whole address in its own right. So, for now, just trust in your own inner light that is a spark of God . Such belief and Trust is all you need.