When I was 17, my family went on vacation to Canada and left me home alone.
It was before cell phones, so I had no way to contact them easily.

They were supposed to be gone for seven days.
I stayed behind working my summer job and taking care of the house.
On the seventh day, something strange happened.
A postcard from my mother arrived in the mail.
It said they were stopping in Vermont and returning two days late.
I read it and felt relieved they had updated me.

Two days later, my family came back home as expected.
They apologized for coming back later than planned.
I told them I already knew about the delay from the postcard.
My mother immediately went pale and looked confused.
She said they had never sent any postcard at all.
She also said even if they had, it would not have arrived that fast.
I insisted I had seen it clearly and even read it.
But when I checked the counter, there was nothing there.

No postcard, no writing, nothing to prove it existed.
Only my memory of holding it in my hands.
I started questioning if I had imagined the entire thing.
But something about it felt too real to dismiss.

Because if no one in my family sent that postcard… then something had entered our home while I was alone, left a message meant for us, and vanished without leaving a single trace behind.
And the most disturbing part was that I might have been the only one who ever saw it.