Be on the same wavelength and Fall in

Fall in and be on the same wavelength are semantically related. In some cases you can replace term "Fall in" with "Be on the same wavelength", this terms are similar.

Fall in verb - Break down, literally or metaphorically.

Be on the same wavelength and fall in are semantically related. Sometimes you can replace phrase "Be on the same wavelength" with "Fall in", this terms are similar.