My DS. Is 3 and has also recently become scared of the dark. I got him Russell the dream sheepdog which is a cuddly toy who's tummy lights up when you squeeze his paw. It's quite pricey but seems to have helped - though the problem is still with us to a lesser extent. I liked the idea of him being able to control putting the light on and off at will. Also,we keep his bedroom door open and a light on in the hall so his room isn't exactly dark so I thought a light he could have right next to him would be a comfort when he needed it.