Rather obviously inspired by Siskoid's 5 Sci-Fi Films To Drop The TARDIS Into...
Doctor Who has never been above a bit of creative recycling. Quoting Robert Holmes: "We only use original ideas in Doctor Who. Not necessarily our original ideas." This was the writer-producer who set a Frankenstein story on a distant planet and did a Mummy story with robots, so he knew what he was talking about.
So anyway, four supernatural or paranormal threats and one exaggerated natural one. Going full paranormal or SF-horror would have been too easy...
A parapsychological experiment to find "sensitives" and study their responses to a house regarded as haunted, cursed or "unclean". Nothing is directly seen, but is the overwhelming sense of foreboding only the atmosphere of the house, or...? (For a less ambiguous version, maybe Poltergeist, complete with solvable mystery and big implosion at the end. But not the Haunting remake.)
A natural threat, but far stronger than normal, threatens a tourist attraction, and the town's rulers won't listen to reason and warn people off. Put that in space and imagine the Doctor dealing with a monster he can't argue with and a human authority who ignores his arguments.
Something Wicked This Way Comes
A circus comes to a small Depression-era town, arriving unannounced, bringing strange temptations and perhaps, just perhaps, relating to a string of disappearances in other towns... (Ray Bradbury could fuel a series of Doctor Who by himself. And as an added bonus, its Big Bad was the Master for one night only.)
A psychic entity that demands to have its story told... or it will kill you. Can its threat of death within seven days pursue a target through time?
A child marked as a future apocalyptic threat to the world, protected by strange "accidents" and fanatical servants. Is he human? Is he innocent in all this? What do you do?