Coupe is misfiring and there's a ticking noise to be heard - Is i t the ignition leads.

[Robert Stirrat]

Hello there.  My NG engined Coupe has started to misfire.  This doesn't
happen all the time.  I checked the distributor, the rotor arm seems clean
enough and in good condition.

I noticed that if I place my finger close to one of the leads near the
distributor cap that a small spark jumps to my finger tip.  I've tried
reaseating the lead with no change.  Am I right to assume that the
insulation has broken down and that this leakage will cause cause the spark
at the plug to fail to move ignite the mixture.  There appears to be two
ticking sounds I can hear one from the distributor cap, is this normal? The
other is from the engine block is this because the piston is being pulled by
the cam rather than the the internal combustion?
PS. The oil level is fine.

Will replacing my leads solve this trouble?  Thanks for any pointers on this
one.

Robert '92 Coupe