"Letter states sharing, isn't that for uploading a file?"
Please don't use that as a defence - and it's probably best you Google how exactly torrents and file sharing works.....
I hate to say it, but in 99% or more of these cases, the letters ARE correct.
Without knowing how many people are in your household with access to the internet, can you categorically rule EVERYONE out?
If anyone in your household is using a fork of Popcorn Time Movies (after the official one was closed in 2015) then that uses torrent sharing to provide the video feed.
In this day and age if you (as in the general public) are going to watch ANY video files you haven't paid for, you really need to do your homework.
And use a VPN.