I think the terms are getting you a little confused.
X10 devices are transmitters, receivers, or transceivers. A transmitter transmits X10 commands over the power line while a receiver receives commands and controls a load. A transceiver converts non-X10 signals (IR or RF) into X10 commands.
What you need is a wall-mounted transmitter which can send commands to control your lamp module. You'd remove the existing switch, wire the outlet so that it's hot all the time, and install the in-wall transmitter such as the XPT1 or XPT4, either of which is $21.07. There are fancier, more expense in-wall transmitters but these would be fine for a kids room.[Link: homeautomationnet.com]
Just disconnect, cap, and label the traveler that's currently providing the switched power to the switched outlet so that the system can be restore at a later date.