When I was a kid the "toy" to take apart was a disposable camera. The sort you used to buy on vacation and then drop off to have the film developed without getting the camera back. I discovered after charging it that touching the capicator gives a nice electrical shock. I spent a great deal of effort teaching this painful lesson to anyone I could trick into learning it.

The objects of curiosity don't need to be a toy, or even meant for children. Anything that can be disassembled will be disassembled by a curious child.

Too bad it's no longer possible for end users to disassemble mobile phones.