My oldest went through this stage of life it is called Nightterrors.All kids will go through this at some point.My youngest is going trough this now.We found getting a night light in the room works and we also gave each on a flashlight to have on in the bed. Show them how to turn it on and off.
This has been really effective for us.Try getting one that you can charge the battery as to safe money on batteries.
And since we all check on our kiddos usually before we head off to bed,that is when you can turn the light off.Mine usually have no more waking up after I turn it off.
If you do still get up with the kiddo then just console with that mom love turn the flashlight on and leave it on.
If when you ask if they had a bad dream and they say yes,Talk about it and console.My husband and I also found that if he would go in and act crazy like he is looking for the monster or whatever the case.Beating on doors and walss then acting like he is beating the monster up it helps.So tell dad to go act like a clown and make them laugh and smile.
This works better well with our youngest(a girl) and at the time our oldest(a boy).
Good Luck