S.F.
My son did the same thing and then I read something in a parenting magazine which I tried and it worked. In the magazine, they described a similar situation and they then told their daughter they were going to give her a felt flower and she could only use it once to call them up. Once she handed them the flower for the night, that was it - she couldn't call them up again. We tried the same thing but with a red ticket. It worked wonders - I think it gives the child control - they can decide when to use the ticket, but know - once the ticket is used, that's it - time to stay in their room/go to sleep. Hope that works for you!