yeah, the whole conversation about moving the cemetery where they're overlooking the neighborhood was the dad talking to his boss. his boss is complimenting him on being the top house salesman, and how, and a big bonus, he's gonna give him a new house once the new neighborhood extension is completed in a few years.

and the dad's all like, "but where are you gonna build it?" and the boss guy is like, "oh, ya know, the cemetery. we're gonna move it." and the dad is like, "won't that piss people off?" and the boss dude is like, "we've done it before with your neighborhood." and the dad's like, "uhh.... huh..."

that's why you see coffins popping up in the half-dug up pool in the back yard near the end of the film. that's also why, at the end of the movie, when the family runs out of the house, right before it implodes with ghostliness, and the boss guy drives up and comes up to the dad all WTF, the dad grabs the boss and screams at him, "YOU ONLY MOVED THE HEADSTONES! YOU LEFT THE GAVES DIDN'T YOU‽ YOU ONLY MOVED THE HEADSTONES!!!!"

which means the dad is pretty much the only one who figures out why any of that crazy shit actually happened.

edit: ok, time for a rewatch. that movie is sooo good