My Dog Are Getting Weird Recently

recently my dog ​​barks in the middle of the night around 2-3am it makes me lose sleep, can anyone tell me the reason?
(it also often looks into an indefinite space)

You live in a haunted place. That is the only explanation... leave before it's too late. He's trying to warn you.

If hes sleeping at the time, it could be that he has sleep-barking or bad dreams!