My first thought is that the visiting cat will not go home until it gets that note off. cats are irritated by alien things on them and will be quite adept at removing it.
Trap it and take it to the SPCA and if it has a license they will contact the owner and if not the owner will have to try to locate it or it could be spayed or neutered and adopted out.
I have a female house cat and as I live in the country there are ferals coming around. I do feed them once a day and let them fend for themselves and keep down pests the rest of the time. My cat loves to throw herself at the french doors and carry on and sits and waits for them to show up so she can do that. Mostly they ignore her. There are seldom more than two cats around.
In my area calling animal control is a certain death sentence for a cat. The cattery at the animal shelter is ALWAYS full and euthanazation is carried out pretty quickly if not immediately. There are numerous no kill groups in the area, however they are always full too.