I remember next to nothing, so bear with me.
The time is the present or maybe the very near future. The plot circles around these evil people/aliens/wizards who have the ability to control what people see to a certain extent. Typical behaviour is to make themselves invisible.
The “heroes” are looking for their secret headquarters. Towards the end, they discover it’s a building in the middle of a town/city that no one can see, because all of the people who live there have been tricked into thinking it’s not there.
That’s basically all I can remember. I’ve been thinking of this ever since I drove past an abandoned building site (which was, in the movie, the place where the invisible building was), and I can’t figure out which film it was. Any ideas?