Composite video - relay module

I tried a similar sort of thing using a multi-pole switch, I switched the ground wires as well, it worked but there was a flash and the image was distorted momentarily after switching, the image kind of wobbled and vibrated for a second or two. Then the image was ok, there was no noise after the image had settled down but it didn't seem like it was doing the monitor any good so I used to turn the monitor off during switching as a precaution.
I suppose the electro-magnetic coil in the relay would interfere with the signal wire, could you wire it so the signal wire uses the normally closed position so the relay is not energised when the signal is connected?