Pandemic 2: The land of the infected

1 day later at eight o'clock at night...

"Crap!" Carl excalmied
"What is it?" you ask
"Were out of gas" he replies
"Shit!" you swear "Well, didn't we pass a big manision like two minutes ago?"
"Yeah, I saw the lights were on, there maybe people still inside" he says
"Maybe" you say.

You and Carl, totally armed walked down the road to the manision.

"Well this is it" says Carl.
"I wonder if this house has a doorbell?" you wonder, the door to the house was three stories wide, it look like if it was something out of a horror movie. You find find a big switch next to the door. What do you do?