The fuse installed in an electrical plug is a vital safety device. A filament inside the fuse is designed to melt and cut the circuit if the current gets too high. This prevents damage to the appliance or electrical device, the person using it, and stops the power cord from overheating to the point where it could catch fire. Two fuses are typically found in the electrical plugs of miniature holiday lights to prevent overheating, and possibly exploding the little glass bulbs. Replace the plug fuse to keep your electrical appliances working.
Remove the plug cover either by unscrewing it, or sliding the cover off the plug base, which is the main part with the two prongs for plugging into an outlet.
Use needle nose pliers to remove a blown fuse -- the small, glass tube with metal ends on either side. You can tell whether the fuse is blown by examining the glass tube. It will be dark and smudged, or the visible wire inside will be broken.
Insert a replacement fuse with an identical amp rating into the metal brackets of the fuse housing.
Replace the plug cover.
Only replace a burnt-out fuse with an identical, matching fuse. If the device calls for a 3.5 amp fuse, use only a 3.5 amp fuse as a replacement. Failure to do so could cause a fire, property damage and death.