Yes, I enjoy that too. Found film unprocesed in a camera is a special treat. Not that I really need another instamatic or 35mm point and shoot, but if that is the price of the film, well...
Buying old prints of unknown families happens sometimes too. Oh, and slides. I have a series of a couple on driving vacations all over north america most years between 58 and 74. The guy was a pretty good shooter, and edittied what he put into the slide carousels. His kids cleared out most images of the individual family members, and then put dad's images up for estate auction. out of seven carousels I repacked them down to take the spaeces out and ended up with 3.75 full carousels after a bit of light editing of my own. They are most fascinating to look at.
Also another series of slides for someone who rode horses competitively and went to florida to ride in the winter a few years in the mid 70's. I end up with them as part of a lot buying up some old maps. Estate auctions are a dangerous hobby that way.
I ended up with about 50 slides of a guy who died of a heart attack. They were in a box that I really wanted for the old Norman pack and head 200B flash rig. That rig now is most relaible,a nd well worth the $15 she wanted. The images are a nice bonus. Him hanging out with his friends mid 70's and off to surveyors camp, so I suspect he studied enginering at one stage. The sides have his pals names on the mount. I have yet to google them up and put a thread of them together.