How do you function in office jobs where there's nothing to do?

Guys I'm going crazy. I'm doing a summer job right now before going off to grad school but there's literally no work for me to do. I'm on week 2 here and last week I logged about 5 hrs of actual work and this week is looking the same. I'm going completely stir crazy I need more work or tasks cause I don't know how I'm supposed to stare at this computer all day trying to look busy when I have 0 tasks. And yes I've asked my boss and coworkers if there's anything they need help with and nope nothing. How do y'all handle being so bored but not being able to do anything? Like I can't play video games, work on one of my art projects, watch YouTube so what do i do? Each day feels like 20 hrs at work