I have a database in where I have found some field with NON UTF8 characters inside. In fact, if i edit the field value with phpmyadmin, copy the value of the field, paste it on notepad++, and change the encoding, I see this character  while there is nothing if i change the charset to utf8 no BOM.
I need to find a way to search and delete all those ANSI visibile characters in the mySQL tables, consider that those character are visible only if I paste the value in notepad++
please if someone has an idea, anything is apreciated.
this question is related to this problem:another question
You can try this:
select * from tableName where fieldName regexp '[^ -~]';