If the number is substantially higher than the number of tax returns you've prepared and you suspect possible misuse of your PTIN, complete Form 14157.
If the number is substantially lower than the number of tax returns you've prepared, you need to verify that you are entering your PTIN correctly on returns. The most common cause of this problem is the entry of an incorrect PTIN during tax preparation software setup.
I doubt that it is someone uses my PTIN or I did not enter PTIN on my return. I am wondering why it should be off. It is a simple count by computer and should be 100% correct, no?