not sure if commenting on laser safety will get this thread shut down but, depending on the age of the building I’d not only want to solidly identify the material but also be concerned with anything it’s been exposed to from paints to pressurized insect treatments, fire retardants lots of things I don’t want the fumes near me for.
For instance nice “safe” plywood isn’t always sometimes the glues used from one brand to another may not be. So please be careful.