Well I hope he knows what you see in Amsterdam windows ain't whats waiting for you in the back-shop.
(Allegedly...a friend told me on a stag in 1975)
Not the most exciting thread ever posted in the NAAFI but I know out there in the world of ARRSE someone will know the answer.
We’ve got an electrical box under the stairs that we don’t know what it does and it’s got a red flashing light. Can’t photo the light so I’ve drawn an arrow to point it out.