How do you do a bug sweep for electronic bugs such as hidden cameras and audio equipment?

Hidden cameras I know can be detected with laser detectors. The laser reflects off the lens, the detector detects it and so on... audio bugs are hard to detect. You could use a device that measures radio waves but it would have to be very sensitive. Also, don't forget that there is a difference between a tapped phone line and a bugged one. A bug is essentially a transmitting microphone planted anywhere to monitor you at low risk to the eavesdropper. While a phone tap is a line that basically splits off of your phone line and goes to somebody else's phone (and from there maybe even through a walkie talkie or other device to reduce the risk of discovery). It is the same principle as listening to your sister talk to her boyfriend in her bedroom via the other line in the kitchen. It is high risk to the eavesdropper but can only be detected through counter-surveillance. You can buy such equipment on the internet. It's sketchy, but at the same time, when was the last time you found the spy department at K-Mart? (There isn't one, I'm kidding)