A Letter Arrives in the Mail

It is the middle of the summer holiday, and you stand in front of the door of your home after a long day of doing absolutely nothing.  You put the key into the lock and turn it to hear the familiar sound of the pins giving way to unlock the door.  It falls open.  You call out to see if anyone of your family is home, they are not.  You step over the threshold and close the door behind you.  Nothing is out of the ordinary, why would it be, it's just a normal day in the middle of a normal summer.  You start to head toward the kitch...ah! You lose your balance as your foot suddenly slides out from under you as if the normal friction that would accompany your step had been replaced by a banana peel.  You almost fall head first into the ground when you catch yourself on the wall, barely.  Regaining your composure, you notice that what you slipped and fell over was not an item from the bag of tricks of a vaudevillian jokester, but an envelope.  This strikes you as very peculiar seeing as how the mailman tends to use your mailbox on the road instead of walking all the way up to the door in order to use the mail slot.

It is just a normal, nondescript, nothing-out-of-the-ordinary-here envelope, accept for...something.  You pick it up, and examine your find.  The texture is soft, yet crisp, light, yet firm.  It is sealed with nothing other than one of those old-timey wax seals that you only ever see in old movies where everyone talks like Humphrey Bogart and is always dressed like they are going somewhere important. You are pondering the nature of the weird little thing as you walk into the kitchen.  You are about to discard it on the counter for your parents to discover when they get home from work when you notice that it is addressed to you!  Not only your name and address, but to the location of your room in your house which you had just moved into after trading with your sibling the day before!  This is weird, you think, how could anyone possibly know that?  And yet, they do.  This is all too creepy. You are about to open the peculiar parcel when you second guess the idea.  What if there is poison inside, what if it has a chemical to set the house on fire, what if it is addressed to the wrong person?

So what do you do?