We begin with the caveat that Ripley's is not exactly a rigorous scientific survey. Nevertheless, it presents us with some interesting information. According to the above link, over half of UK adult's surveyed believe in ghosts while only about a quarter believe in God. (I am sure that the results would be significantly different if given in the US, at least the numbers.) I find this question fodder for this site not so much because of the low numbers related to God, but the disparity between the two. Some assumptions have to be made, or at least some questions have to be asked.
Does a disbelief in God equate to a rejection of religion in general? I think its safe to say, at least for the sake of argument, that they do. Given that most organized world religions require a belief in some sort of divinity, although some might be practiced with out that belief.
Do those who believe in God overlap with those that believe in ghosts? Not necessarily, but I again think its safe to say that the majority do. It is far easier to explain the concept of ghosts if we have a religious framework to put them in.
Which of course leads to the issue at hand. About 30% of those survey, at the very least, believe in ghosts but not God. Belief in ghosts, in and of itself, is by no means odd, no matter what moderns might say. Ghost phenomena are one of the few universals in world cultures. Ancient Sumer, the earliest known producers of writing, believed in ghosts. As do the ancient cultures of India, China, Malaysia, Africa, and the Americas. In one form or another every culture has ghost stories.
But they all exist with in the framework of religion.
A belief in ghosts is, in itself, a kind of faith. It is faith in an afterlife. There are some other assumptions in any belief in ghosts. Ghosts are the spirits of humans, or at least most of them are. Not everyone becomes a ghost, right? So, by what mechanism are ghosts made and consigned to this world? What happens to everyone else? Even if the answers to these questions is "I don't know" its still a belief system. A belief in something beyond this life.
In an ideological vacuum this belief in ghosts would likely spawn its own religion. Some anthropologists in fact believe that is the origin of human religion. Asking questions about death that lead to more complicated systems. In our world of a myriad different belief systems ghosts seem to have broken off into their own little pool of belief, one that seems independent but relies on the context of the larger religious culture. It is not logically possible, ate not logically likely, to have ghosts and not have divinity, gods at least if not God.
Aliens? Fine, you can believe in aliens, and even UFOs, without a need for religion or God. Ghosts? I think its highly unlikely. Angels? How can more people believe in angels than in God? Angels are by definition messengers of the divine. So unless the respondents are defining their terms in some abnormal ways, very likely, this survey leads to a lot of questions.
Which I guess just goes to prove that we need a wider dialog on these issues, find some common terms, and figure out what is going on in our heads if not our world.
PS If you believe in ghosts but not in god, I would love to hear from you.