Take a computer apart and you may find how interesting it is. All the wires and chips are fascinating. You will see what connects to what and how some things work. If you want you can even clean out the dust in the computer or any other items. 

If you take apart a speaker its is pretty cool. In the speaker, depending on how big it is you can find a big or small magnet. The bigger the speaker the bigger the magnet. It is pretty cool. You can use the magnet for putting things up on the refrigerator. Just somethings I thought you may find cool.