an interesting wall switch (faulty)

[The Ghost]

I think these are 5v sensor pads which can adhere to all sorts. It's a postage stamp sized pcb. Perhaps this one???
http://www.sensor.co.uk/pdfs/Tile-mounting-diagram.pdf

 

[buzzlightyear]

I cant take the tile off as that needs to be done by the tiller

f***kinhg hell cant see one of them on wall.

 

[7029 dave]

Relocate the switch to the wall outside of the bathroom like most normal people would do, unless you live in the dark ages and have a bit of string attached to the ceiling.......

I would.

 

[Dave OCD]

If you have access above to the light and wiring you could disconnect the dodgy sensor and fit a wireless switch on the front of the tile.