a navy electrician friend who just passed away. told stories about how he tested sockets on the ship by wetting his finger and sticking in the light socket. i think he had a high level tolerance for voltage.
Not Me! No Way! Though aboard ship, each leg of the 120 Volt circuit is 60 Volts to ground. I used to test transformers. And using an Isolation transformer, I could make bare handed live 120V connections and not feel a thing. One at a time though. Using only one hand.