There are many causes of pinholes leaks in copper tubing. And the time it takes them to eat rough varies widely; from just a few years to many. The cuaes are acidic water or soil, electric grounds and your electric gorund electrode, certain bacteria, dissimilar metals, soldering flux, non-reamed tubing ends (erosion), high DO, CO2, chlorides and TDS and lightening strikes. I think I have them all.
The electrical (and water company guys) tend to fib bu saying what you heard but…. you seem to have an electrical problem that needs t obe checked out by an electrician.
Quality Water Associates