Using Google, search for Dr Hulda Clark and or Dr Clark and or Zapper.
The ground and the square wave output are connected to 2 short copper pipes with aligator clips or soldered, then wet paper towels are put arround them (the pipes) and you grab with one hand one pipe and with the other hand the other (of course), for the Zapper's operation details read the stuff posted by Dr Hulda Clark on her site.
"Warning" If you use a hearth pacemaker or are pregnant then don't use the Zapper nor any of the other BioElectric-Magnetic electronic Zapper devices.
Zappers are sold on the net already made, but is cheaper to make your own.
If you need more details let me know.
There are other simple bioElectric-Magnetic electronic devices that you can make or buy if you want to experiment with them, more details on another blog.
These devices are said to be harmless to people (if you don't wear a pacemaker or are pregnant or have a hearth condition) but deadly to bacteria and viruses that might be in your body, but don't take my word for it, use Google or other search engine like AltaVista and look arround in the Web (Internet).
"Warning" use any of these or other such devices at your own risk.
You are the only-one responsible if you do and neither me nor anybody else is, including those who sale any such devices.
People who use them, say that those Zappers and all other such devices have to be used very often on a regular basis for very extended periods of time to really be efective and also that it's best if they are combined with each other alternating them and also with other therapies and or proper diets.
If you are sick, seek the "proper medical (Medical Doctor) attention".
And you are responsible for your own health. And you are the only one responsible for what you do or don't do.
Some more on another post other day soon.
For more info, use a search engine to look for answers, also I might, on another post give a little more info.