What if there is no load connected and there is no current flowing? The clamp meter will read 0 amps but the cable still has potential to kill someone.
Then he can't use a current clamp meter for that.
There are commercially made instruments that will detect a live mains wire several inches away, even when it's not carrying current. Don't know how I would make a detector that does that.
Voltage detector - Wikipedia, the free encyclopedia
"AC detectors"
"A very different kind, also called an AC detector, detects the electrical field present around any wire which is connected to an AC source of 50 or 60 hertz. It never touches the wire, and typically has both an LED that glows and an audible noise. These get brighter and louder as the field increases closer to the wire. AC detectors can be used even if no current is flowing through the wire in question."
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Now I get it. The OP wants to make such a device himself.
I would start by experimenting with an FET. These can detect static charge from several feet away.
If a mains wire is nearby, an FET will respond with square waves. Because it is greatly amplifying nearby sine waves transmitted from mains wiring.
It needs an antenna connected to the input terminal.
Many IC devices have sensitive enough inputs to do the same thing. (Although they're not as sensitive as an FET, unless they have FET input.) That's the reason for advice to connect unused inputs to supply + or ground.
Just by touching one finger to the oscilloscope lead, I see sine waves which are several mV amplitude.