Or use candles either side of your TV
I kid not, the sensor bar is infra-red, its there only to locate where the wiimote is in relation to the sensor/TV, anything that gives infra-red will do
You can build a much better sensor bar using high power infra-red LEDs, but then you need an external power supply, I've seen them powered by a simple PP9 9V battery, costs a few pounds to 'adapt' the original to provide better response