Afraid of the Dark?

We just got a whopping hydro bill--over $200 for two months of electricity and hot water. Could it be because E. insists that we leave the lights burning all night so that she can sleep?

For the last couple of months, she has been SCREAMING and jumping up and down in her crib whenever the light is turned off. We tried a night light, but that didn't create enough light for her. So we bought energy-saving bulbs for the hallway, but she hated them because they were too bright. We've now settled on leaving the bathroom light on from 7:30 pm to 7:30 am. Yikes.

Is she afraid of the dark? I have a feeling that seeing that light on assures her that we're close by, and personally, I have no problem paying the cost of nightly electricity for a good night's sleep.   

However, now she's progressed from begging me to leave the light on to begging me to "SIT DOWN MOMMY!!! SIT DOWN!" I can handle the tears of frustration and the screaming for a certain period of time, but sometimes she will not give up. I feel like we need to let her cry it out, or I'm going to end up sitting in her room for an hour every night.

I expected this when she was a baby. But no one ever told us that we'd be doing this at 2 years old--at an age when she can string enough words together to make me feel REALLY, REALLY guilty if I don't go in and comfort her.