Hidden cameras can be very hard to locate and may require you to go over everything with a magnifying glass looking for tiny pinholes in objects. Signal Blocking Bags like the spy finder allow you to look through the red glass view hole to locate cameras. Originally designed by the government, the spy finder shines its LEDs at the pinhole camera and causes a reflection when it locates the lens. Sometimes, this is the only way to find the hidden camera.

You can use an ordinary flashlight to create a reflection from a camera lens, as well, but it is more difficult and you will have to be standing right in front of it.

Simply leaving behind a cell phone is the most common way to bug an office.  It may be left behind in an obvious place as if someone “forgot” it, but more likely it will be dropped in a plant or hidden somewhere with a Velcro mount.  Voice activated recorders are probably the next most common thing to look for and are often hidden the same way. Therefore it is better to put a mobile jammer in office.