Traditionally, dowsing was done using a forked branch or stick to indicate subterranean water, minerals or even grave sites. The end of the dowsing branch would bend downward when held over the water source, mineral site or body. A divining rod was commonly made of a forked branch from witch hazel.
Dowsing or divining rods can also be made of metal, and bent in an "L" shape - one for each hand. In ghost hunting, when the rods cross while being held out in front of the "dowser," they are thought to be indicating a spirit presence at the spot where the dowser is at. This type of dowsing rods may also be used to divine "yes" or "no" answers to questions, the crossed rods indicating yes answers.
In the real ghost hunting photograph, notice the orb captured above where the metal dowsing rods have crossed. Energy is possibly present.
This vintage illustration shows a man using a witch hazel tree branch as a divining rod (Y-type) to detect water sources that are hidden underground. This same method is sometimes used, today, to detect graves without markers in old cemeteries.
More on Divining Rods Used in Ghost Hunting: Ghosts & Dowsing