4 year olds

Lately, Hannah has been struggling with sleep which means I don't sleep either. When she was two the train that she could hear during the night even if she was passed out scared her. Last year it was the cars driving down the street. Now, it is the smoke detector. I kid you not. The smoke detector. The red light on it scares her. She can't see it from her room, but she knows it is there and it bothers her. She peed her pants last night because she was too scared to leave the room to go to the bathroom. (The smoke detector is next to the bathroom.) It took me two hours to get her to settle down so she could go back to sleep. This is happening every night, and I am starting to go crazy. The only way she will go back to sleep is if I am sleeping near her. One night I slept on the couch and she slept on the love seat. Most nights, though, I end up sleeping in her bed until she falls asleep and I use my stealth ninja skills to sneak out of her room. This child has always struggled with sleeping. I was full (and still am) of irrational fears as a child so I am trying to be patient. My parents addressed it by saying I could sleep on their floor if I felt scared. Unfortunately, E isn't too keen on that idea which means I am stuck trying to find ways to keep her in her bed. His solution is to let her cry until she falls asleep. That way doesn't work because she always wakes Meeghan with her crying so then I have two children awake at 2am and a sleeping husband who isn't helping. I am at a loss. She won't go to her room or the bathroom during the day unless I go with her. Anybody have any suggestions? We have discussed that the smoke detector won't hurt her. I am about to cover the lights on it to see if that helps. I don't want to disconnect it or cover it completely.