During the cold days I noticed a little draft coming from the light switch next to my house door. Removing the switch revealed that the tunnel for the cables was widened to fit the cables for the electric strike control right next to it. The hole measures about 1/2" in diameter.
Is there a preferred way of closing this? By default I would either use the silicone caulk I have still around or get some expanding foam. As I am no electrician I do not know how accessible one should keep those wires. (Silicone caulk would be easier to remove as foam as far as my experience goes.)
Here's a picture