Getting tomato spaghetti sauce off the roof...

[Indadhanu]

Hmmmmm if paint is coming off from just wiping it, not much else is going to work I don't think :-(

[Rouge]

Sounds weird but a UV light would work.

[Pandora]

Where would one get one of those?

[Rouge]

Google UV torch

But they can be dangerous so make sure you keep it away from kiddies. I'd even be inclined to take it apart and put half in one place and the other half in another.

[diva det]

i have had this happen before lol - how sad is that
i got it off with ajax bench spray- the one in the yellow container- the trick is to do it straight away
otherwise if you get desparate maybe a bit of domestos on a sponge and blot the stain- domestos gets everything off!!

[emc2]

Bleach and then rinse it. Something thick like Domestos as it's on the ceiling.

Magic erasers do actually remove a small amount of paint.