Put it in his electrical box. The next time he has to go reset a fuse he'll open it up and see shit everywhere it'll be hard to get out of the crevices of each of the switches
That a long term stealth one.
If you want a quick instant gratification you could do the oldie but goodie called the upper decker or you can leave a present under the pillow on his bed or you could leave some under the driver side door door handles on his car
