Some people prefer to have their lamp switches in-line on the cord. This is especially useful for desk reading lamps where the cord is easily accessible. Also, some lamps may not come with an on/off switch and if you do not have an inline switch for these, you would need to turn the lamp on or off by unplugging it or having it plugged into an outlet controlled by a light switch. With a few tools, in-line lamp switches are installed quickly in existing cords.
Unplug the lamp cord from the wall outlet. Pick the location on the cord you would like your in-line switch. Slit the cord in the middle for a total length of 3/4-inch with a utility or pocket knife.
Find the smooth, non-identified wire. It has no ribbing or indentations. Cut this wire in the middle of the slit with your wire cutter.
Place the cord into the designated wire channel on the in-line switch. The cut wire should butt up to the terminals in the switch while the other wire runs straight through it.
Push the two switch halves together. Tighten the screw to secure the halves together.
Plug the lamp into an outlet and test the in-line switch to verify that it works.
Be sure to unplug your lamp before attempting to install a switch. Failure to do so will cause a severe electrical shock.