Okay, let's work through this. I believe in ghosts, a hundred percent, so I'm not going to say "ghosts isn't real ur stupid kid" and expect you to thank me for such a well-sourced answer. But I'm also not going to go off on a religious rant and tell you to pray to Jesus or Allah or the aliens for forgiveness, so let's just work on the facts you stated and what they might mean.
Yes, I too have heard that ghosts / spirits can cause atmospheric disturbances like 'cold spots' in a house. In fact absolutely everyone knows that, because they've heard it many many times. But here's the thing: While everyone has heard that, nobody can say where they heard it or how they know it's true. Of all the people who said it's true in your life, how many of them have provided any kind of lookable-uppable source? Exactly. And lookable-uppable is a real word.
The answer is nobody. A superstition is something that everybody knows, because everybody has heard it from many people, but nobody can provide anything to back it up. Just like how everyone knows that dogs and cats can see spirits, or how everyone knows that you shouldn't summon the dead chick who lives behind the bathroom mirror.
Now let's look at buildings, which I actually do know a few things about. I've been in the businesses of constructing, repairing and insuring buildings for over 25 years, so I've learned a thing or three about them.
And all buildings do that. Buildings are designed and to have air flowing through every part of them, because airflow is essential to keeping them standing. But perfectly balanced airflow, while it would be ideal, is literally impossible. There will always be that one room that's hotter / colder / dryer / damper than the others, because that's just how reality works. Even the most advanced HVAC (heating, ventilation, air conditioning) system on earth has limitations, and those limitations are based on variables. Area of each room, ductwork, external and internal climate, exterior exposures, insulation, elevation above sea level... all those things are factors in the equation. There are so many variables involved that it's simply not possible to make the airflow the same in every room in every building.
So what have we learned today? We learned that the ghost-temperature thing is a completely untested theory, and that buildings by nature don't perfectly balance a constant temperature in every room.
Still think there's a ghost in your house? Or could it be all that other boring stuff? You decide.