Meadowbrook, New Jersey, looks like it’s right out of an old-time postcard. It has a big town hall, with huge columns and a neat border of red tulips. There’s a quaint little Main Street, its wrought-iron lampposts twined with evergreen sprigs at Christmas; a big green park, where the kids trace ice-skating loops on the frozen pond.
The town is nestled in a valley, and on one side is a steep incline that thrusts up into the ravine, where some of the expensive modern houses are perched like wood and glass boxes. On the other side the larger homes slowly give way to two-family houses and apartments on...