This method is 100% undetectable (well I have yet to be caught using it)
This is a old method I used and still working. I only tryed it with my mouse.
Here is what you do, get a fan 80mm or 90mm or whatever, just a fan that is small from or for your computer.
In the middle of the fix where it spins, make some short of mark on it, if the fan is black make white mark with whiteout or something.
Take that fan and place it outside your case, leaving it working and on.
Place your mouse (I have lasar, might work with optial, but not sure) over where you made the mark, your cursor on the screen would make random movements because of the fan is spinning and your mouse is picking them up as its own movements.
My explantion might be little bad so I am posting pictures.






