Yes, they do go through a fear-ful stage around 2 and also around 3 for some kiddos.
We had to try several things before we found what worked. A night light, leaving the door open, and cuddle toy in bed, and lots and lots of reassurance worked for us. We also used phrases that helped him remember that we'd be back if he needed us... so we always went back if he called. Then said, "I'll stay 1 min and give you extra hugs, then it's time to sleep. Mommy is here if you need." Then I would leave. I would return if he was distressed and say the same thing. I would ask how big he'd like his door to be open and that kind of helped distract him.
Other moms here have had to directly address fears... whether they were shadows, or whatnot. My DS did ask about some shadows on the wall, but I showed him it was the curtains and we later played with shadows and lights with a flashlight... basically made it a "fun" thing and not a scary thing.
Most importantly, if you stay calm and keep it light and fun, it'll help in the long run. I know it's not easy so hope this helps.