This CRT is confirmed to be a hot chassis, possibly with very slow high voltage bleeding.

Hot Chassis means that "ground" on the chassis is tied to one side of the AC input from the wall, and touching it with your hand will complete a live circuit through your body to earth ground if the CRT is plugged into an AC outlet. The proper way to avoid this danger is to use an isolation transformer to isolate the CRT from earth ground and prevent electrocuting yourself.