Anyone know of a safe and simple way to find an ignition wire that is making a weak and not visible discharge to ground?

I have a 1995 Magnum 5.9 V8 in a Ram

On the AM radio i can hear a zap-zap-zap of what appears to be just one of the eight ignition wires.

It is a slow paced zap at 580 rpm idle speed so I don't think it is the coil wire.

Even in near complete darkness i cannot see anything.
No blue green corona discharge.
No flash from a spark.

I have looked at and felt the wires and cleaned them with WD40 before reinstalling.

I have thought of pulling off
one at a time
each wire end connector at the distributor,
or of grounding one wire at a time,
but i want to be extra cautious because
I have read in the past
of 1994-1995 OBD-I Magnum V8 owners
"Frying" the Triac switches that are internal to the JTEC computer, which is expensive.

I own a simple inductive timing light.

I have one of those cheap spark checkers that goes between wire and sparkplug with a neon bulb.

I have an Actron Scantool OBD-I with the Chrysler cartridge.

There are nearby friends with fairly extensive tool collections i might be able to borrow a specific diagnostic device from.

I have thought about borrowing or buying an extra long "known good" ignition wire and substituting it for each of my present wires one at a time.