Two firms face prosecution by the Health and Safety Executive after the death of a teenager electrocuted on a Bala industrial estate two years ago.
Miall Gwyn Roberts, 19, was killed by 11,000 volts of electricity while laying concrete foundations.
R L Davies & Son Ltd, from Colwyn Bay and Permanent Flooring Ltd, of Bagillt, Flintshire, face two charges under the Health and Safety at Work Act 1974.
They are due to appear before Dolgellau magistrates on 11 September.