File kind presence

[Simone D.]

Hello,
is it possible for monit to check the existence of some file with 
particular extension?

For example:
i want to be sure that there isn't ANY file .txt in my directory 
/home/foo/ (and in its sub-directories). If there is at least one I want 
monit to alert me

Looking into docs I found the rule to check the existence of a specific 
file but i didn't find anythign about a "general rule".

Thank you very much,
Simone