I am fixing a shelf in my closet. The shelf rests along a piece of wood nailed to the wall. That wood that is acting as a base for the shelf has separated from the wall. Apparently whoever built this didn't secure it to the studs, but instead nailed it to the drywall and just got lucky that they never put any weight on the shelf.
I pulled/snipped all the nails and will be using screws to fasten the base back to the wall before replacing the shelf.
Anyway the wood is slightly warped. I can press against it to flatten it, but I can't do that while also drilling new holes and adding the screws. Since this is inside a closet, I figure I can find something like a Ratcheting Cargo Bar or the reverse of a ratchet clamp to press against the opposing wall to hold it in place. The space is slightly less than 2 feet wide.
Does a tool like this exist and what is it called?