If it is mains voltage, get an inline connector unit, B+Q etc do them, IF low voltage, ie about 12v from a transformer, you could use crimp on bullit connectors, male and female one available, Car accessories shop type of place will do them, OR you can get two wire connectors that are orientated so that polarity is correct, again car places, OR model shops, they are used as battery connectors etc on models
SD, March 2012