There have been many posts about using X-10 modules outdoors particularly at Christmas. I thought it would be helpful to post three different solutions that I have found to be handy and reliable. All are used with GFCI outlets for outdoor decorations at Christmas time. None of these has ever triggered the GFCI outlet whether it was raining cats & dogs or they were buried in fresh or melting snow.
The first is the most complicated and would be suitable for year round use. It's made of light weight sheet aluminum and has been in service now for 12 years. The module is under the cover.
(http://www.sfpasc.com/x10/MetalCover.jpg)
The second is made of a baggie within a baggie, tied with garbage ties, held in place by a rock so the baggie opening is down. The connection to the GFCI outlet is by an extension cord. There is no protection at the outlet for the extension cord plug except the hinged lid of the outdoor outlet cover. This design has been in use for over 7 years. The module with a cube tap for the two decoration cords and the extension cord outlet end are all inside the bags although you can't see them.
(http://www.sfpasc.com/x10/DoubleBagged.jpg)
The third is new this year but I think it will be as reliable as the others. The zip lock bag is over the whole outlet, appliance module and light cord and is held in place with a wire tie, in this case two since one wouldn't be long enough. NOTE: Now that I've looked at the picture on the Forum I think I'll try rolling up the excess bag and securing it with transparent tape so it looks neater.)
(http://www.sfpasc.com/x10/ZipLockWireTie.jpg)
Hope these work for you too.