Hi sKalley,
The 7th Day Adventists were founded by Ellen G White ... she was a follower of the Second Advent movements in the mid to late 1800s ... these were started by William Miller ... Nelson Barbour was a follower of Miller ... and Nelson Barbour later became associated with Charles Russell, greatly influencing Russell's thinking and views of time-line prophecy ... so, the JWs are connected to the Second Advent movement ... and if you attend the 7th Day Adventists you will find many similar doctrines, like a paradise earth, no hell, etc ... but they are not as cultish as the JWs ... yet they do shun what they call "Apostates."
A good friend of mine is an ex-JW Presideing Overseer ... he was also 7th Day Adventist the fist half of his life ... now, he is viewed as an Apostate by both religions. Double Whammy ... yet he is a good man, and wouldn't not harm a fly.
Amazing