3 year old daughter - terrified of unlocked doors and wants mom to lock them

So this all started when my daughter turned 3. She would freak out whenever someone opened the back sliding door or when someone would come through the front door. She freaked out, cried and has 3 year old type panic attacks until my wife/her mother picks her up, walks over to the door and locks it all - all while my daughter is watching and monitoring the entire process. If my daughter is sidetracked and doesn't see the actual motion and process of the locking - she continues to freak out again until she witnesses it with her own eyes. Then after my wife does that- she runs to the sliding door screaming and demands my wife unlock and relock the sliding door (which was never opened during this entire process).We have been researching on this and see that it could be a phase - or there is a safety aspect that maybe only her mother can lock the doors securely and then the house is safe ? But it's really getting to us now and we're about to just start letting her freak out tomorrow morning and stop this whole locking process while calmly explaining that the doors are still locked - no one unlocked them , and it's safe.Honestly I/we are not sure what to do. If you ask her to come for a ride with you she's happy and leaves and goes outside like nothing is wrong (so she's not actually scared of outside) she even plays outside just fine..but when she's back she goes on an insane freak out until my wife goes around like a maniac locking doors - it's really taking a toll.I mean she's F'ing 3 years old - it worries me that she clearly has this illogical fear of unlocked doors - and scares me even more that there is a neurotic component here (with the act of watching her mother lock and needing to be held during the process)It's literally driving me insaneAnyone ever gone through this ? via /r/Parenting http://ift.tt/2ahdXEY