The House With a Clock In Its Walls is another kid-stays-with-eccentric-relative story, though this time the child has been recently orphaned instead of just visiting for the summer. It's a deceptively sweet story that packs a creepy wallop, even getting downright scary in a couple places. (I've since seen it described as a "gothic horror for children," if that gives you an idea.)
The Edward Gorey illustrations definitely add to the creepy gothic vibe....
...I really like Lewis, the kid in question. He's unapologetically bookish and awkward and fat, and he makes the kinds of mistakes we've all made in our struggle to be liked, so you can't help but cheer for him.
The [book] is actually an old book, first published back in 1973, but there's nothing to date it other than that cover up there. (In fact, I had no idea it was that old when I read it - I figured it was from the nineties.)