Well, you don't say what country you live in. But here in the UK there's tons of the stuff; all in flower at this time of year. It wouldn't taste very nice; but it's not a "deadly" poison; although it might make you ill!. When the berries form, in late Autumn, some "country" people hang bunches in the doorway; it's a sign of peace and hospitality. Some mothers still hang a small bunch of mistletoe over the baby's cot!
However, although there is still a lot of mistletoe here, there is a lot less than when I was a boy. Many of the birds that feed on the berries, especially the mistle thrush, are in decline.
Mistletoe will grow on any tree except pine. In old times, when it was found growing on an oak tree, the tree was called a "sacred oak", and the mistletoe cut from it was used in fertility rituals.