Earlier quoted context omitted.
My dad drilled water wells in the US after spending many years working on oil wells overseas. His clients would often hire witchers (water witches, water witchers, well witches - I think the distance from Appalachia to Montana clouded the specific vocabulary). You'd have this very old man dodder around the property with a pair of sticks, and when the sticks magically chose to pull together and cross, that's where you…
It's called Dowsing and there's no evidence that it works. https://en.wikipedia.org/wiki/Dowsing
Waking back and forth across the front lawn the bent coat hangers crossed consistently along a line so he started digging. Unfortunately the pipe he holed with the garden fork was the gas supply and the day ended with the gas company coming around to patch the line. I don’t think we ever found the water stopcock.
Though we can’t explain it dowsing does seem to work. There is however no guarantee that what you find is what you were looking for…