Yes, from the few that I've seen, usually there is a wire that either wraps around the plug lead, or attaches to the plug itself.
I wrote to the Tech Support at TrailTech, and he suggested that a points system will not allow the tach to function correctly. My only thoughts were it might be due to the quality or type of electrical signal picked up by the tach lead, that might differ from points to electronic ignition, but I lack the experience here to really know.