Then you've got a frequency zapper, not a clark style one. I'd be careful--it might well have those human frequencies on it. I think the ones sold here are only one of at least two zappers being used for the testing.
If you feel anything more than a tingle which might sting a little (not enough contact--giving yourself electrical burns), turn it off. I'm getting it's randomly triggered so you might try turning it on again and see if it come on right again. It never should give a current that makes your muscles bunch or anything like that.
But that means it has a frequency setting for fungus. If you can keep it from electrocuting you, that's great. I got one for fungus specifically and it helped get rid of the cancer fungus a lot.