Human beings have a pretty weak sense of smell compared to other mammals. That's why when we smell a bad smell, it seems especially disturbing because we often have trouble ferreting out its source. We end up pacing back and forth all over the place sniffing deeply, loudly, and idiotically.
Back in the day (like pre-VCR when you had to watch movies on network TV with eight zillion commercials and dub-overs), my favorite movie was Steven Spielberg's Poltergeist. It had all the trappings of a really great kiddie-level horror story: a PG-13 rating (somehow always scarier than "R" due to a necessary reliance on psychological terror tactics versus gore and violence); a creepy blonde kid (played by the late Heather O'Rourke (see below)); an even creepier fortune teller/kindly grandma figure with a high squeaky voice who looked and sounded like a little old lady version of Yoda (played by the late Zelda Rubinstein); and, in classic Spielberg-fashion--lots of ghetto early 80's special effects done with electric fans, clay models, and cardboard mock-ups. If memory serves, the plot of Poltergeist was basically a creepy kid being stalked by mischievous ghosts (poltergeists) who were obsessed with her for no apparent reason.
Well, that's how I feel when I detect an appalling smell somewhere and can't figure out what it is or where it's coming from. I call this "The Poltersheist." I don't claim to have invented this term. In fact, I would credit it to a friend if only I could remember who actually coined it. But it's quite a fitting description for those smells that stalk you mercilessly like the nefarious ghost of actual shit, resurrected from the dead to taunt you and make your life miserable and unpleasant. What is it? Where is it coming from? Is it moldy soup? Is it truly the ghost of shit-diapers past, or is it actually a live shitty diaper that remains very much in play within a toddler's pants? Is it rotten salmon skin in the garbage that someone forgot to take out after last night's dinner? Is it a dead animal? Like maybe a mouse that got into your dishwasher and couldn't escape? Is it in the sink? Under the sink? In the garbage disposal? In your fridge? Your freezer? Is it cottage cheese? Bleu cheese (makes sense)? Is it wet clothing festering away in the backseat of your car? Did someone's dog take a shit in the backseat of your car? Or maybe a cat vomited there? Holy fuck...is it ME?! WHAT IS IT?! WHERE IS IT?!
It's at these times that you feel like you're going crazy and no one believes you. And you would give anything to have that sweet, creepy little old Yoda grandma lady from Poltergeist hold your hand, guide you to the spirit world of bad smells, and put those angry poltersheists to rest once and for all. Or at least until the sequel.