Name of this Horror Movie?(:?

Hii! I remember watching this movie, ( I thought it had to do with the
tooth fairy and there was this legend that the kids talked about?) and
it was this black floating ghost thing that could only stay in the
dark, but can never go into the light. The opening scence is this kid,
trying to sleep in the dark, and the creature comes and kills his
parents, but he hides in the bathroom with the light on until police
came. He grows up and in his house lights are ALWAYS on. He has
drawings of the thing that came that night, and if he were ever to be
in complete darkness the thing would finally get him? ohh and there
was this Hospital scene where the lights were out, but the safety
lights were on, and they were trying to get down this hallway, but
there were spaces with no light, so they had to be careful..the ghost
got the nurse I think.. Hmm and in the end, they went to the
lighthouse and finally shined that on it, killing it. Ring any bells
to anyone? Its killing me not to know! haha I thought the movies name
was 'The tooth Fairy', and unless there are too, thats not it/: Thanks
to anyone who answers!