The key card does not open any house. You use it much later to enter the underground treasure trove of the black widow.
you get in the boat and sink
It will.
In the clown store
Once you get the card you see the black widow on it and go to that house and go inside with the key and you will find the the painting and click on it then once you find the door use the card.
Nothing right away. Eventually you get into the black widow's lair and use the card to enter her trove of stolen art.
Nothing right away. Later you use it to enter the Black Widow's stolen art room and battle her in it.
if you want keycard then go to poptropicahelp.net and do island guide
It lets you play the Haunted House mini-game. (a Halloween game from 2009). You can use the card to enter, then leave the Haunted House game, if you have a glitch that keeps you from moving, or when you have completed an island. The card exits to the Island Map, not where you were when you used it.
There is nothing to do with the key card immediately. Go back to the museum to find a package waiting for you. You will be leaving Counterfeit Island (temporarily) to travel to another island, for some valuable information.
The key card is for later. Return to the museum, where you have a package waiting for you.
its on the edge of the dock
you go to the art musem