Where are acpi event scripts that are binded to keyboard shortcuts?

[lubuntu_mailing_list at marco.sulla.e4ward.com]

Hello all. I'm Marco and I use Lubuntu on both my desktop and laptop
PC for many years.

I installed Lubuntu 14.04.1 on my laptop, a Lenovo B590. Since some
keyboard shortcuts are missing (Fn+F3: switch screen) or misworking
(Fn+up, Fn+down: change backlight level) or simply without NotifyOSD
message (Fn+F5, toggle wifi), I would edit them manually.

I discovered with acpi_listen that all these shortcuts are associated
with an ACPI event. So I tried to run the scripts inside /etc/acpi:

/etc/acpi/asus-keyboard-
backlight.sh up
/etc/acpi/asus-keyboard-backlight.sh down
/etc/acpi/asus-wireless.sh
/etc/acpi/ibm-wireless.sh
/etc/acpi/tosh-wireless.sh

No one works. Even if it does not work very well, the backlight
shorcuts do change the backlight level. The shorcuts really launch
those scripts, or there are other scripts elsewhere?