Drilling and sawing walls can be a tricky proposition. The undertaking often requires a plumber or an electrician. Today you'll learn how and where to inspect, so your home and project won't be wrecked. Checking before cutting or drilling into a wall could avoid a big surprise (and repair) because there could be all sorts of things in there -- pipes, wires, vents and ducts. Few walls are free and clear of internal items and a little pre-inspection can stave off problems -- things like cutting into wiring or triggering a gas leak and an explosion. First look in the attic and-or basement to see where any wiring, pipes and ducts may run. Remember to check adjacent rooms too. Then go outside and look for roof penetrations. Last, but not least, invest in a stud sensor. The x-ray was discovered on this day in 1895, launching a new era in medicine and, with inspection, you too can launch a new era of x-ray safety and sanity for home repairs. And that's the On The House tip for today.