There are many different reasons why this article is a bad idea, but none-the-less as someone that likes to tinker (not spy), I like to play around with different methods of tapping my own POTS (plain old telephone service) line. First, before you even think about doing this for any unscrupulous or unethical reasons, you should familiarize yourself with your local, State, and National laws surrounding wire tapping to make sure you are not attempting something that is illegal. You can read more about wire tapping laws with additional links on wikipedia.
Since I am just wanting to show one method of passively listening to your own phone line, I am going to keep this relatively simple and just utilize some basic supplies that you should already have lying around the house. If you are extremely lazy you can easily go to just about any spy gadget store (online or offline) and just purchase a line tapping device that will allow you to record your own phone line and/or do just about anything you can imagine with wire tapping. However, since this article is just for some personal fun we will use common household supplies to get the job done.
Things you will need to get the job done:
1) An old phone cable that still has the jack on it.
2) An old set of headphones (I chose one I bought from an airline).
3) A pair of scissors or a wire stripper (in a pinch you can use a butter knife).
4) A soldering iron (okay if you don’t have this you have another choice).
5) Electrical tape.
Okay, if you have collected all of the supplies then we are ready to have a little bit of fun. Here are some simple step-by-step instructions:
Step 1) Cut the phone line/wire making sure to leave the plug intact (the thing that goes into the wall). Make sure you leave enough wire or line to be able to sit comfortably by a wall outlet to eventually listen to the calls. Then you strip the wire casing back about 1/2″ to 3/4″ to expose one red and one green wire.
Step 2) Strip the red and green wires back to expose the copper wires.
Step 3) Next cut the headphones so you have one of the ears/speakers and a line that dangles about 4″ to 6″.
Step 4) Strip back the plastic casing from around the exposed headphone wires to expose it’s copper wires.
Step 5) Solder the two wires from the phone line and the earpiece together.
Step 6) Cover the exposed wires with electrical tape.
Congrats! You can now plug the telephone jack into the wall and listen to any calls made on that phone line without having to worry about any noise being transmitted from the tap (as you have no microphone, just an earpiece). NOTE: this does not allow you to record the calls at least not with any great quality, I guess you could hold the earpiece up to a speaker or tape recorder. Again, recording is not the objective of this particular tap just the ability to listen on the line.
Once again, I have to warn you to be aware of any laws that may be applicable to using this type of device and act accordingly. It’s amazing the number of variations to wire tapping that you can find on the internet. If you find this device interesting I recommend that you do a search in Google to see all the possibilities. It’s almost ridiculous how many ways a person can tap a landline phone.