I bought a pair of K-1000s and there was a lot of negative energy in my bank account. Even before I received them. Can you imagine that?
More seriously, though, I've got a good story. In undergrad, my friend Jeff had an old TV set that would mysteriously turn itself on. I did not believe him at first, but I saw it happen more than once. It was built before IR remotes, so it wasn't someone else's remote accidentally turning it on. Very, very creepy. One of his roommates would beg him to get rid of it.
Unfortunately, there's a rational explanation for it. When I started getting into old radios, tube gear, audio gear, headphones, and the like, I learned that some older TV power supplies would deteriorate and turn themselves on.
As for older gear, I have a bunch of old tube radios and have collected for ten years now. The oldest is a 1920s Atwater-Kent neutrodyne set, but I have a lot from the 1930s through the 1960s. All of them have had previous owners and been exposed to (I suspect) all manner of human activity. That being said, I haven't seen anything that could be considered a haunting. Unrestored sets have done some weird stuff when I bring them up on the Variac (I replace the filter caps immediately, then slowly bring the sets up to see what, if anything, is going on with them). But I've always nailed that stuff down. Sometimes it's an old wire that's shorting a little under the insulation and sometimes it's a carbon resistor that starts misbehaving when it gets warm. But there's always an explanation and there's always a fix. Once restored, they perform beautifully.
As a side note, there are few things better than jacking a good pair of headphones into a 1930s-1950s era communications receiver, aka "boatanchors" because of their weight. They have *excellent* AM and shortwave reception, and are really a joy to listen to, especially with good headphones. You would wish there were more AM stations playing music.
