What is conductive paint, you ask? It is a paint that can conduct a low-level electrical current once it is painted onto a surface and dries. There are different conductive paints and inks that can be bought in jars and pens from various vendors on the internet, or you can find instructions for making your own versions, like these. You can also use Google or Pinterest to find ideas for lots of cool projects using the paint you have bought or made, including projects for kids. Below I mention some that I found interesting.
This is one from Bare Conductive: http://www.bareconductive.com/make/
Here is an Instructable: http://www.instructables.com/id/Fun-circuits-with-conductive-paint/
Maker Education: http://www.makereducation.com/bare-conductive-paint.html
For more information, check out these webpages: