Oscilloscopes often pick up some small voltage at 60Hz when the probe isn't connected to anything, and that voltage increases when a human touches the probe by

Oscilloscopes often pick up some small voltage at 60Hz when the probe isn't connected to anything, and that voltage increases when a human touches the probe by acting as an antenna. But this is because of the scope's high input impedance(1-10MΩ); as soon as you try to power something off that, the voltage just collapse to zero.