What is a one-sentence summary of the following article?
A tap detector is a physical device you can hook up to your phone. As the name suggests, it can pick up on outside signals and taps, letting you know that your suspicions are correct and that someone else has been listening to your calls. The usefulness of these devices is in question, but in order for any such device to be of any use in detecting a wiretap, it will need to be able to detect electrical or signal changes over the phone line being tested. Look for a device that measures impedance and capacitance levels, along with high-frequency signal changes. For smart phones, you might be able to install a tap detecting app that can pick up on tap signals and unauthorized access to your cell phone data.  The effectiveness of these apps is debatable, so even these may not provide you with irrefutable proof. Some apps of this nature are only useful in detecting bugs placed by other apps. Apps that claim to detect bugs include Reveal: Anti SMS Spy. If you have strong reasons to believe that you phone is tapped, you can ask your phone carrier to check using professional equipment.  A standard line analysis performed by the phone company will be able to detect most illegal wiretaps, listening devices, low frequency devices, and phone line splicing. Note that if you have asked your phone company to check for wiretaps and bugs, but the company refuses your request or claims not to find anything after barely searching, there is a chance that it could be administering a government request. If you have strong evidence that your phone really has been tapped, you can also ask the police to check. Moreover, you can enlist their help in catching whoever is responsible for the tap, as well. Most police departments have the equipment needed to test your phone for a bug or a tapping device, but if you do not have decent evidence that your concerns are justified, they might not be willing to use it.

Summary:
Use a tap detector. Install an app. Ask your phone carrier for help. Go to the police.