There is a mushy patch on my ceiling surrounded by my room, what could be cause this?

I am buying a house and a plant...
Answers:    could be your roof is leaking or if nearby is an apartment upstairs or a room above you then something is leak.
Which colour to paint my room?
Either the pipework in your loft is leak or a tile has slipped on your roof.
What's the significance of chandeliers within homes? What...