Should Ground and Either Neutral or Hot be Lighting Circuit Testing?
Because Black = hot and White = neutral is not actually a hard and fast rule in household wiring. You are probably looking at a switch loop - no longer approved for new installs, but approved recently enough to be quite common. The white wire that's hot SHOULD be marked in some way to indicate that, but often is not, or the marking was impermanent. Red tape or paint or black tape on white wire are common methods of marking a white as not being Neutral.