What is the origin of the idiom "on the same wavelength" and when to use it?

The idiom "on the same wavelength" originated from radio communication technology. In radio, different stations transmit signals at specific frequencies or wavelengths. When two or more stations are tuned to the same frequency, they can receive and understand each other's signals clearly. This concept was metaphorically adapted to human communication and is now used to suggest a shared understanding or agreement between individuals.