fire
That reminds me, I used to like to play with fire in my room. Mostly lighting candles and putting stuff nearby to burn. But one time I had a fire just absolutely erupt, and it probably would have at least set something else on fire if I hadn't had it going in a tin and quickly put the cover on to smother it. That tin got absolutely caked in soot. I think I might have caused the smoke detector in the hall to go off, too.
Another time, I believe inspired by some Donkey Kong cartoon going on at the time, I decided to hollow out the globe in my room so I could have a secret place to store things. I managed to cut the thing in half, but at that point I found out that the thing was made of cardboard and wouldn't hold up very well in such a condition, so I was left with an empty globe stand and some useless bits of cardboard.
Also, before my parents got cable (which was relatively recently) and I was maybe like 12 or 14, there was talk of running a line from the tv antenna in our attic to the tv in my room. For some reason, I got it into my head that I should start making a hole. With a pocket knife. My parents weren't too pleased with that.
And back to taking thing apart, I used to take all kinds of things apart as a kid. Toys, handheld games, hot glue guns (when I took one of these apart I decided to plug the thing in and press the two heater elements together, causing a shower of sparks), batteries. Usually I managed to put things back together, or they were so useless it didn't matter that I couldn't (or they contained mechanical clock parts; damn springs are a bitch to put back in), but there was this one time that I disassembled a computer and printer. And couldn't figure out how to put it back together. Luckily it wasn't our main computer, just an old computer that was put in my room and given to me to use, but my parents were still none too pleased.