Because mush of the home automation material involves working with electrical appliances and devices caution must be exercised. Batteries as small as 9v have enough current to kill a person under the right circumstances. Household AC (120, 208 or 220) can kill very easily under most circumstances. If you are not qualified to work with electricity I recommend you use a qualified electrician. While he may cost you extra money he may save your life and property.
None of the information or opinions expressed in this presentation are paid for. They are strictly my own and my not represent an endorsement of someone's project, product or service (unless otherwise stated so.