I have a few old 24V solenoids which I've used for years for random (often Halloween-related) projects. I can't recall where I got them. I'd like to get some more, but new ones can be rather high priced.
I sometimes buy junk printers to salvage stepper motors, or dismantle speaker cabinets to acquire a driver.
What old equipment commonly includes solenoids that I can salvage (push or pull type, 12-24 V)? Pinball machines seem to be the most-cited, but I never see those at the thrift store.