Hello, I get a straggler spark about every 15 seconds from the distributor cap to some engine tin.
The tin is pretty close. 3/4 inch or so.

Spark shown with a little lightning drawn on there.

Should I take out my distributor, with the gear shaft, rotate counter clock one notch?

Click to view attachment

Change the cap and leads?

I would check the plug too. That jump seems much harder than across the spark plug... Perhaps the wire isn't seated well.

might pay to check the rotor as it will look crappy like the cap ,plugs etc so you are somewhat part of the way to doing an electrical ignition service.
Things that come to mind including stuff mentioned above are ,leads,cap,rotor,points/ condensor,plugs,and then check the wiring to coil and condensor etc,reset the timing after.
You have a high resistance on the lead shown as it is tracking to earth on the engine tin so most likely that lead is poo,you can still buy the Beru copper leads as you have now,but you can buy better ,good luck.

Electricity will find the path of least resistance, so the gap between the insulated wire to the engine tin has less resistance than to that spark plug.
New wires, cap, rotor, points, condenser and spark plugs should cure the problem.