Question about stray voltage

I felt a very slight feeling when a tiny cut on my finger touched water today. Almost like getting lemon juice in a cut but not as intense. So i started fiddling around with plugs and realized when i pulled the skimmer plug i didnt feel anything. Which would normally tell me to replace pump..

However, after plugging pump back in i again didnt feel anything. Could this be me getting used to it or could it he a problem with the actial powerstrip itself? What equiptment do i test this with for real and how do i go about testing correctly?

Thanks
Scott