Crews from five stations battled the fire at Futurist Sound and Light in Otley last night.
Around 50 per cent on the building in White Swan Yard, Boroughgate, was involved in the fire.
A spokeswoman said the single story building was loaded with cables.
Four pumps from Otley, Cookridge, Rawdon and Shipley were sent to the scene just before 9.30pm.
An aerial appliance was also dispatched from Bradford Fire Station.
Crews used four breathing apparatus, two hose reels, two large jets, positive pressure ventilation fans and thermal cameras to bring the fire under control.
One crew remained on sight into the early hours as they continued to damp down.