Why can't I use an X10 Wall Switch Module to control a fluorescent light?
The main reason why standard X10 wall switch modules cannot be used to control a fluorescent fixture is because it is a two-wire device and is therefore wired in series with the load. The control signals which are transmitted onto your house wiring have to pass through the incandescent lamp (load). However, a fluorescent light contains a ballast which acts as a block to the X10 signals and makes it impossible to control the switch remotely. Also, this ballast is an inductive load (a coil), and controlling such a load could permanently damage the wall switch module. This is why the standard X10 wall switches (WS467 and WS12A) should NOT be used to control any kind of appliance (such as a ceiling fan).
To control fluorescent fixtures use the X10
Note that these versions require a neutral connection and are therefore recommended for installation only by a qualified electrician.