#add new rule
sudo vim /etc/udev/rules.d/01_gamepad.rules
ATTRS{idVendor}=="<vendor ID>", ATTRS{idProduct}=="<product ID>", RUN+="/usr/local/bin/<script to run>"

#to get vendor and product id
lsusb

#example output
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 008: ID 045e:028e Microsoft Corp. Xbox360 Controller
Bus 001 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
#example Xbox360 vender=045e product=028e

#another way without lsusb
cat /proc/bus/input/devices

#example output
I: Bus=0003 Vendor=045e Product=028e Version=0110
N: Name="Microsoft X-Box 360 pad"
P: Phys=usb-0000:00:1a.0-1.5/input0
S: Sysfs=/devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.5/1-1.5:1.0/input/input37
U: Uniq=
H: Handlers=event23 js0 
B: PROP=0
B: EV=20000b
B: KEY=7cdb000000000000 0 0 0 0
B: ABS=3003f
B: FF=107030000 0

##after adding rule restart udevadm##
sudo udevadm control --reload