The first thing is a vet check to be sure there isn't anything wrong like a UTI.
Where did you get Caleb? Was he already litter box trained or was he outside? If he was already litter trained then maybe he doesn't like the type of litter you have. It may be very different than what he was used to. It is strange that he used it before and just now started this.
I would vet check soon and talk to your vet about what he is doing. Caleb may also be stressed for some reason and this is how he is trying to tell you.
Putting him in the bathroom at night won't hurt him but be prepared for lots of crying. If you do decide to do that then make sure you put his bed and litter box in there as well as food and water.
Good luck and keep us posted on how he is doing.