What's causing this staining of wallpaper?

[Steve4Nature]

Hi, my first post as I venture into buying a home and doing it up.
The house I want to buy has orange-ish dotted stains on the wallpaper at a few various locations around the house (some high, some low). It feels dry to touch. Any ideas what this is?
Very grateful for any advice.

 

[Brigade77]

That is a heavy anaglypta type wallpaper and those stains are a sign of dampness.

Do not worry. The dampness would appear to be atmospheric, that is . . . it is not necessarily the worse kind of damp.

This doesn't mean that a simple redecoration will solve the problem, it means that you need to understand not only what the stains are, but also how to prevent them happening again after you re-decorate !

 

[Steve4Nature]

Thanks Dork Lard. Very useful. Based on your comments I think the problem might be caused by a poorly ventilated bathroom nearby.