How do I avoid cables when drilling or hanging pictures?

Cables to a light switch usually drop from the ceiling, so the wall directly above every switch is a likely path. Power points are fed from above or below, so the same goes for the wall straight above and below them. Cables also run between outlets, along the top of walls near the ceiling and around door frames.

In older brick veneer and weatherboard homes in Altona, Laverton or Footscray, cables often hang loose in the cavity rather than following neat lines, and past alterations may have taken any route. Check the other side of the wall too: a power point on the back of a shared wall means a cable inside it. Water and gas pipes sit behind kitchens, bathrooms and laundries.

Detectors that sense live cables only find wires that are switched on and not too deep, and foil insulation, metal studs and brick can confuse them. Stud finders find timber, not wires. Neither can see a cable that's switched off or a pipe behind tiles. Use them as a guide, not as proof that a spot is clear.

Use adhesive hooks or picture rails where they'll hold, choose short fixings and set a depth stop on the drill. Keep away from the strips above and below switches and power points. For a wall-mounted TV or heavy shelving, it's worth having an electrician put in the power point and cable route at the same time, so nothing ends up hidden in the wrong place.

If you do hit a cable, it can stay live and heat up inside the wall even if everything seems to work. Repairing it is licensed electrical work.