Were one of you pedants in HOF in Norwich?

[2point4kids]

I was in House of Fraser in Norwich yesterday and somebody had corrected a poster in the ladies toilet for using unecessary apostrophes.
It tickled me, thought it might be one of you lot

Disclaimer: I am not a pedant (and am typing one handed with baby on lap) so please don't tell me off for any errors in my post!

Sorry but I can't help but snigger at Norwich.

I reside in Norwich but it wasn't me.

Wasn't me, I dwell in Norwich too but I'm more of a QD girl ...
So what did the sign say? Please wash you're hand's?
I've never been one of these people who correct posters, I think it's a bit disrespectful actually and a bit obsessive even if there is a mistake. Do they carry a marker pen especially for the purpose?