Can anyone tell whether this is a drain cover or an electrical outlet cover? Former homeowners converted a garage to a family room ~20 years ago including extensive water drainage reorientation. The room appears to have been carpeted at one time. Photo shows a 5+11/16" circular brittle plastic cover with a 4" capsule-shaped recess holding two metal screws (rusted and stripped) on either side of a large 4-sided phillips-shaped indentation (shallow, stripped). Original color (grey? or white) obscured by cement treatment. It rises 3/8" above cement floor level. If it's an outlet, we want to use it; whereas, if it's a drain, we want to leave it alone.
My bet would be on it being a receptacle. Typically floor boxes like this are installed raised up a little, so as to accommodate carpet or other flooring.
I would also bet on it being a single outlet. Most likely the center cap is covering the outlet and the outer screws are there to hold everything on. Since we can see a shadow from the center box, I'd say pry it off of there as best you can.
It's hard to say, but looks like an outlet to me. It should be safe to use an appropriately sized philips driver to open the plug in the middle and look inside. (It looks large. Don't strip it with a small driver.)
It's an electrical outlet cover. We had them at one of my previous places of employment. We actually had two separate sets of them offset by a few feet under the floor of office space. The second set was for our computer networks. The center plug is to keep debris out of any outlets not in use.