By which I mean, not the usual ghosts, but ghosts of things that were dead to start with.
There are many reports of phantom coaches, ghostly ships, even ghost cars.
Oh, I've heard the argument 'but horses will have spirits' and 'coaches and old ships were made of wood, which comes from trees, and they were alive', but the arguments don't hold.
Horses might well have spirits. So might trees. But a car? Does iron have a soul? Does aluminium have an afterlife? Is there a Windscreen Heaven? I find that hard to believe.
Besides, why would four ghost horses consent to pull a phantom coach? Surely they'll have better things to do?
On the coach itself, yes, it's made of wood - but that wood was cut, shaped and polished from felled trees. It was already dead before it was made into a coach. The ghost, if there is one, will be that of a tree, not a coach.
Yet the reports persist. Ghost coaches, ships, cars and trains are heard and seen. Too many to be written off as imagination or hysteria.
I have theorised previously that spirits might vary in their ability to produce manifestations of themselves. Some can appear with perfect clarity, a few even in daylight and with such detail that they are mistaken for living people until they vanish. Some produce hazy forms, some partial apparitions, some just blurs. There are those that cannot appear but can make raps, or voices on a tape. Many, I suspect, cannot interact with the living at all.
So at the top end of this range of skills, it is possible that there are a few highly-skilled apparition-producers who can form the illusion of a vehicle. It won't be an easy thing to do, but since a spirit has no form, the image they manifest does not have to be limited to a replica of the body they left behind.
Currently, my interpretation of ghostly vehicles is that they are projected by highly-skilled spirits, and are in fact nothing at all to do with the vehicle that might once have existed. They might be recognisable to us because the spirit has modelled the manifestation on a car, boat, coach, whatever, that was important to them, or to which they were particularly attached.
The spirits involved must be very powerful. How much effort would it take to produce a ship, or an entire train? Perhaps a group of spirits work together on the bigger images. There are, after all, a lot of dead trainspotters out there. It's not much of a stretch to think they might get together to relive their previous obsessions.
I am, as always, open to alternative interpretations, unless you want to tell me that metals have souls. I can suspend disbelief only so far.