Book involving children traveling between alternate worlds via switches

Question

I know I read this after 2012, I think as an ebook. The cover depicted a knife switch by itself, I think closed with the handle up. At the beginning of the story, the protagonist, a boy, is told by his friend at school (another boy) about a strange house on the back of a flatbed truck in their neighborhood which they explore after school. It was a small house, like shed-sized, I think with red walls. They find the door is unlocked and inside, there's a switch, I think described as being like the ones in the cover image. I don't remember if they opened the switch, closed it, or maybe tried switching it a few times, but seemingly nothing happened before his friend runs off, saying they need to get home.

The next day, the protagonist finds the world around him has changed. His family treats him in a subtly different way (I want to say that his parents got along better). His school has him enrolled in different activities. Strangest, he's friends with a bully from before, and his friend he was with the day before is afraid of him. I think he finds the house from before and tries the switch again, and winds up in an even different world where that house doesn't exist. I don't remember exactly what happens, but he winds up friends with another boy, who takes him to a homeless man (either the boy or the man had a fancy name, maybe Shakespeare based) who has talked about switches and other worlds. Said man, I think, has a respiratory illness, and he makes them a meal on a hotplate plugged into the building he's squatting in. After talking to them, the man shows them a switch in the basement of the house, which the two boys pull to go to another world.

I forget the details, but they went through several worlds. One involved a theocratic dictatorship with a guy with a fairly normal sounding name, and where they also encountered that homeless man, who didn't recognize them, but still gave some good advice. Another world was a hive mind world, I think on the shores of Lake Michigan (maybe an alternate Chicago?), and I remember they had to recover someone, and at this point they'd been joined by a girl. A later world was a tropical paradise where they found the friend from the beginning, who's served hand and foot by the natives, and who doesn't want to leave. When they try to remove said friend, the natives get violent.

Eventually, they wind up in a very alien world, I think with crystalline grass and telepathic quadrupeds, and they find a man in a building who explains the nature of the various worlds, and that he serves some purpose in keeping them all stable with the controls on front of him. He needs a replacement, and one of the kids volunteers. When he touches the controls, he rapidly ages into adulthood, I think as part of the training process, and sends them home to their original realities. After returning, the original protagonist encounters the boy who was left behind, now elderly, and I think realizes he knew him from before.

The book was in English, and might have been targeted for teenagers, as I remember there wasn't any real sex or violence.

Answer 1

In the process of writing the question, I started thinking it might have been named The Switch, so I started searching for that name, and site:goodreads.com "the switch" parallel worlds got me A.W. Hill's The Switch.

IMAGINE THAT you could change your world with the flip of a switch. You might be prettier, more athletic, more popular, or even living on an exotic island, because your history—your world line—would be different. But here’s the catch: you have no way of knowing if the reality on the other side of that switch will be better…or much worse.

JACOBUS ROSE is a fifteen year-old who believes—as many fifteen year-olds do—that his life could use improvement. School is a numbing routine, and his parents’ marriage seems to be imploding before his eyes. ‘Maybe I was born into the wrong world,’ he thinks. Lured by his best friend, CONNOR, into a strange little house containing nothing but empty rooms and an oversized circuit breaker, he’ll discover that reality comes in a plural form, and that our choices create a continuous web of branching worlds, any of which is as ‘real’ as another.

A solo odyssey becomes a duo, a trio, and then a quartet, as Jacobus befriends other interdimensional travelers along the way: GORDON NIGHTSHADE, the veteran pilgrim and chief theorist; MOSES DeWITT, the alley cat with an old soul; JEMMA DOONE, a girl of many-worlds who becomes the main river home for Jacobus and his crew; and finally, his lost friend Connor, who just may have preferred an alternate universe to his own.

THE SWITCH is the story of their journey home. The question is: if they get there, will it be the same place they left behind?

And indeed, the cover shows a knife switch, although it's more colorful than I remember.

I also misremembered the homeless man who goes by the "Duke of Earl".