No, you just think it is. The intruder must be there to commit a further crime, usually a violent one.

   An intruder must be making (or have made) an attempt to unlawfully or forcibly enter an occupied 
     residence, business, or vehicle.
   The intruder must be acting unlawfully (the castle doctrine does not allow a right to use force 
     against officers of the law, acting in the course of their legal duties).
   The occupant(s) of the home must reasonably believe the intruder intends to inflict serious bodily 
     harm or death upon an occupant of the home. Some states apply the Castle Doctrine if the occupant(s) of the home 
     reasonably believe the intruder intends to commit a lesser felony such as arson or burglary.
   The occupant(s) of the home must not have provoked or instigated an intrusion; or, provoked/instigated 
     an intruder's threat or use of deadly force.

https://en.wikipedia.org/wiki/Castle_doctrine#Conditions_of_...

No, you must reasonably believe they intend to commit a further crime.

Here, unless you give them a reason they're just like "yeah, dude opened the wrong door, heh?"

I am aware of a few southern states where the statute assumes the intruder intends to harm you. UncleEntity is likely correct.