If electricity is flowing through the tank, you'll need to find the source of the current. Use a voltmeter and unplug each piece of equipment to find the culprit. You can temporarily use an unraveled cloths hanger to put one end in the tank and one end into a grounded socket, or a screw on the front plate of your grounded power outlet box. It may temporarily relieve some stress.
We need your water parameters, lighting, etc. etc. Find out if anything has died, and test for ammonia immediately.