child's DIY mechanical toy panel

Once upon a time I saw a panel that had a light switch, receptacle and plug, screen door hinge and latch and other things a child could do to keep busy and learn while they are playing. Do you have any ideas of things we could add to the panel. It will not be electrified but could have some battery operated things. Something that makes sounds would be nice too.
 This child is two and seems very interested in stuff like this.