Our JP recently received a ticket from a city officer, who was out in the county, in his own private vehicle, off duty, not in uniform, who issued a ticket to someone for unsafe speed. I know that the jurisdiction is not a problem, since he was in the County in which he works as a police officer, but never heard of anyone doing this off duty without just calling another officer to come take care of the problem. Anybody see a problem with this?

Most police agencies discourage off-duty policing except in the most extreme circumstances. It's just not good policy and would likely to lead to more problems that would exceed the merits. Since officers are generally considered on-duty 24/7, the off-duty officer is probably legal in the traffic enforcement and it would be treated like any other police activity.

Would you stop for a person who was in an umarked car, with no lights etc. Talk about a potentially dangerous situation for an unwary citizen, especially a lone female. Impersonating an officer is not unheard of! Did he make a traffic stop in this instance?
I agree it is bad policy except in exceptional circumstances.