Zombie alert

We recently rented a house in the countryside and we discovered that there was a curious building next door.
It is a small very anonymous brick building with the words Freezer House on a small plate.
Inside it is a bunch of custom built toploading chest freezers that looks like they are 50 years old.
We never see anyone near the building and it looks like it hasn't been used for years.
The freezers however are still RUNNING!
I find this seriously creepy.
Is it some government experiment?
Zombies being kept frozen only to escape the day the electricity goes and they thaw out?
A storage facility for a webring of serial killers?
The other day I saw there was another one a couple of kilometers down the road.
Needless to say, I lock the doors at night....