On the old UK slam door trains they had a pull cord "for Emergency use only". Underneath each cord was a sign saying £50 for improper use. I once saw a sign had been ripped off, and instead was scrawled the following...
If fifty pounds you can afford, go ahead and pull the cord. If fifty pounds you do not own, leave the bloody thing alone!
It made a boring train ride that bit more interesting, al least for a short time.
On some of the Sydney trains there is a sign that reads: 'At night travel near the guards compartment marked with a blue light'
Cleverly some have been altered to say: ' At night rave near the guards part naked with a blue light'.
Again, makes the whole trip more interesting and makes you wonder what someone that cheeky and clever does for work...