Many OLD churches/structures in general have very old wiring.
For example, when Mrs Woodbutcher and I started attending St. Maries Roman Catholic church in Manchester, NH we were given a tour of the entire property. It opened in 1895. The original church built in 1865 had burned down.
The tour included the organ loft. The ceiling above the bellows was covered with wires. Cloth covered wires. The large organ tubes were made out of wood. The first thing I thought was this looks like an electrical fire waiting to happen. there was 100 year old seasoned wood exposed everywhere. Basically, nothing that would even be close to today’s basic electrical building codes. All it takes is one rodent to chew on those wires and cause a short/fire.
I can’t imagine what the wiring may be like in 200-1000 year old buildings. It would all probably be similar because electrical wiring was a 20th century invention.
You bring up many good points.
This was within the USA. The conditions are likely even more neglected in the older countries, where the general job economy stays low.
Maybe the church you visited will be declared a National Landmark and then receive enough money to update the wiring and plumbing. Out here in Ca., it would also need to be earthquake proofed with new structures.