It's best to remove the turkey giblets before cooking the turkey however sometimes people do forget to remove the turkey giblets "Including Myself" and usually nothing too bad happens.
Sometimes the turkey giblets are wrapped in plastic and sometimes the turkey giblets are wrapped in paper and stuffed inside the cavity of the turkey.
Not all turkeys contain the giblets but some do so it's best to check for the giblets before cooking the turkey.
I once cooked the giblets in the turkey before that was wrapped in plastic and it did create a bit of plastic melting smell in the oven and I thought the turkey was ruined however the only part of the turkey that really affected was near the cavity of the turkey and the rest of the turkey was perfectly fine to eat.