Merriam-Webster's Learner's Dictionary
off the hook
with the receiver not resting in its usual position
▪ They took the phone off the hook so that it wouldn't ring.
You can leave this phone "off the hook," but...
you can't leave this phone "off the hook."
You can leave this phone "off the hook," but...
you can't leave this phone "off the hook."
The Amboy Times: Obsession Movie Offends Muslims
''My cellphone has been ringing off the hook . . . We feel that it's going to incite more hate and bigotry against our community,'' said Altaf Ali, Florida chapter director of the Council on American-Islamic Relations.
Can I say that my cell has been ringing off the hook? Is there any expression for the cell phone?
You can leave this phone "off the hook," but...
you can't leave this phone "off the hook."