G.B.
I have a child who at that age would occassionally do the same. It was usually when he waitied TOO LONG to go because he didnt want to stop playing. When he would run it would come out. He also had issues with peeing the bed. not every night, but quite a bet when younger. He is now 9 and does not do these things anymore.
Milk consumption before bed can be a culprit for nite time peeing. Giving extra magnesium can help and also no milk at night.
Also diabetes can show with incontinance symptoms.