It’s mysteriously scary in our new office building…

Our new office building have some strange things to witness. The building entrance is on the back side, 2 neighbour elevators shut open together on one’s call, the elevator indicator shows ‘7’ on the 6th floor. This is all weird, but that’s not the thing to worry.
The scary part was the lift indicator showing floor ’13’ proudly, that the next moment we realized the building is of just 10 floors/storey. What do you think could be goin on?