I have two scopes one analog and one digital. A Rigol DS4024 and the other a Tek 2465B. They both seem to be operating and matching readings on my other exuipment when connected to a circuit. When probes are disconnected they both show the exact same thing and it has me thinking i just don't understand something..... both scopes are set the same, 50mV per division and 5ms per division and are coupled AC. both probes are lying on the bench and not connected to or touching anything. Im displaying a 60Hz signal with an amplitude of 150mV on one scope and 200mV on the other. I'm thinking they are picking this up from the mains somehow but im not sure why that would happen or if this could be messing up signals when im connected to a circuit. Im guessing there is a very logical answer to this but it is not clear to me... Is this normal? If so why is this?