Stray current?
 

Has anyone ever expierenced this before? I was doing a WC and unplugged my heaters. When all is said and done I hook everything back up and I thought I felt a tingle in my fingers when I put them in the tank. Not sure if it's electricity or not? Heaters look fine there 300w. wouldn't that be enough to throw you for a loop if one was shorted?

I'm not a huge fan of playing with electrics but is there a way to test?

thanks