As I understand, it is quite popular protocol for such switches. This ones seem to have some explanations and be useful
Mine is a quite generic no-name remote and socket
Attaching RAW signal from all 8 buttons, each recorded 10 times
1_on.sub (45.0 KB)
1_off.sub (43.1 KB)
2_on.sub (38.8 KB)
2_off.sub (37.7 KB)
3_on.sub (37.8 KB)
3_off.sub (39.4 KB)
All_on.sub (41.1 KB)
All_off.sub (37.7 KB)