I think there's a set-by-teens wildfire in one of the Bill Wallace books (He wrote A Dog Called Kitty and a few others that sort of go with 'kid moves to the country, learns to interact with/respect/tolerate nature/animals/rural things') - but it's been a VERY long time and I can't remember the deets.

Seconding that the second sure does sound like John Bellairs- there's a number of sequels to the House With A Clock In Its Walls.