The phrase "wrong message" means that someone is communicating or expressing something that is not understood or is causing confusion or a negative impact. Full definition
Then again, I can find myself «flirting by mistake» with men I am not even particularly attracted to and that can send wrong messages. (datinggoddess.com)
I guess YOU»RE not as SMART as YOU think BeckyJL — the «message» you took from this isn't what you say it is — put on your regular people had and get off your narcissistic horse — read it again — IN TOTAL this time... YOU got it wrong (drkellyflanagan.com)
This sends out an entirely wrong message of what the DfE perceives to be acceptable practice. (schoolsweek.co.uk)