[FotoPlasma]

I'd have to know more about the situation, but you might look into drilling a hole large enough to snake the wires through the inside of the tube. If you decide to do this, make sure that you protect the wire around sharp edges, or even do away with the sharp edges by filing. The helical wire wrapping material is very handy, but if you don't secure it, you should check it regularly to make sure that it stays in the right place.

If you could post a picture of the situation, it'd be a lot easier to suggest ways of helping.