RF 433 Switch Failing

[Thales Maia]

Hi there, I equipped all my home lights with a RF 433 switch, like the one bellow.

I use a normal three-way switch and a remote (433) switch. To power them, I use a 12V 3A power source and a 33mF capacitor together with the power source.

The problem I'm facing is that from time to time (~5 - 12hrs), with no apparent reason, the relay switches. Since it always switch to original state, I've assumed that it was a power source failure problem. That is why I changed the power source and put a big capacitor. The problem remains.

Does anyone ever used this module? If so, can you tell me if this is reliable?
I needed to power the system of since it was turning my lights on while I was sleeping.

Important detail about my installation. I got lot of CAT5e cables, so I used them with a splitter to power up 12V to the boards.
Also, it seems that is always the same boards that fail.