Sometimes negative energy can gain entrance into even a well-shielded home. It may be brought in by children or pets, or subconsciously by adult family members. Negative thinking can invite and create unwanted energies.
If you feel this has happened, try this exercise:
Imagine a ball of sparkling white light somewhere in the center of your home.
See energy pouring into this ball until it becomes blindingly bright and powerful.
Now allow it to slowly grow, filling your home with white light. Know that this light is cleansing and banishing all negative energy it touches.
See it grow until it spreads through the walls to the outside, completely encompassing and saturating your home with white light.
See it form a permanent, yet *solid* sphere of protection around and throughout your home.
A sphere of light saturates an area and eliminates the *space* for the negativity to exist, so it is great for cleansing and protecting anything - house, car, object, your aura, even your Self.
~from Maat's Book of Shadows