Hi, great question. Unfortunately, the answer is no for a couple of reasons.

1. Mini lights should really not be cut because they are wired in series and their bulbs are rated for a specific current draw. The better choice is to find a string of lights whose length most closely matches your project requirements, or tuck the oveage out of site under a branch or eave.
2. Gilbert plugs are made to punch through the thick SPT-1 or SPT-2 insulation on 18 AWG Christmas light cord.

Thanks for your question and keep them coming.

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