Have you thought about crating him when you are away. It sounds like he is bored. Crating is not a bad thing. It not only keeps your things safe but also keeps you dog safe. You never know what they are going to get in to when you are gone. It could be something dangerous to them and you won't be there to help. My dogs will go into their crates, on their own, to take their naps. Since dogs are naturally den animals, I think they feel more secure in their crate.
How old is your dog? If he's a puppy, that's what puppy's do, and especially when they're teething. Anything that you don't want chewed, keep up out of his way, and make sure you give him his own toys that are good ones, like kongs. Good luck with him.