Wire Bridge

 wire endings seem to lose electricity so having loops is better than bridging. Important buildings better have battery/generator close by until they fix bridge and electricity loss.

Your wires are not connected to the switch correctly, so that might have something to do with it.
The switch it 2 tiles tall. You only have wire connected to the bottom tile of it.
I found to make switches work, it's best to have the wires coming in from the top and bottom.
Every now and then there is a bug where is still doesn't work, but you just need to flick the switch on and off again to fix it.

It's a bug. It's reported already. It's pending.

If someone want to report a bug please, do more work and create steps to reproduce, do some screenshots, test some more scenarios. It is alpha release.

1 hour ago, SpoonsOnMyElbows said:

Your wires are not connected to the switch correctly, so that might have something to do with it.
The switch it 2 tiles tall. You only have wire connected to the bottom tile of it.
I found to make switches work, it's best to have the wires coming in from the top and bottom.
Every now and then there is a bug where is still doesn't work, but you just need to flick the switch on and off again to fix it.

It is not related to switches. Switches work just fine when connected through the bottom tile (upper one is just a light).

It is related with wire bridge. Please see bug report in post above.

Well.. i can confirm that they don't work fine like that, and often do break in the way your picture is describing.
Been testing for over 80 hours now.
I'm not saying that's what your issue is, but dismissing it and saying that's simply not it, and that they work fine is wrong.
The switches and wiring were so buggy so often that i had to completely change the way i wire stuff up.
And since making those changes, it's worked perfectly for at least 1000 cycles.