Are they still there when you save in a non psd format like JPG or PNG? As Bill says, can you isolate it to specific layers? (Hold down Alt or Opt and click on each layer in turn). Is it just this document? I notice you didn't use the plural 'PSDs'. Can you auto select the glitch with the Move tool and Auto select checked in the Options bar?
It shows up when saved as a jpg and other formats... I can't select the glitch and its only this psd file. I tried closing and reopening the file, restart, shut down... Etc... There are white lls and black ones throughout. Whenever I click into any layer it creates those lls randomly... Then the bounding box is expanded. I am using a 2013 iMac 27 inch... dont have full specs till monday because its my office imac. i think 16 gb ram...I've used photoshop for over 7 years and this has never happened.
On the very rare occasions Photoshop has gone weird for me I have got past it by copying all the layers to a new document. Select all the layers, right click and choose Duplicate Layers. Use the Document dropdown and choose New. I have a feeling this will leave the glitch behind.
If the glitch ‘does’ survive the above, save the layered document, and delete the preferences file by closing Photoshop, and holding down Shift Opt Cmd immediately after restating it. If you still have problems after this, get a PC.
BTW I am sure you knew several ways to copy the layers to a new document, and it always feels terribly patronising when you strongly suspect you are teaching grandma to suck eggs, so please ignore the OTT description if that was the case.