I know nothing about Norway but in the US in the early to mid 20th century, electric clocks used the 60 hz frequency of the electrical grid to keep accurate time. They even used to keep that frequency carefully calibrated for that purpose.

But a typical clock outlet is a touch lower then the one here and would never stick out like that. Often they were even set in a bit because you’d typically put the (big, round, analog) clock over the outlet to hide it.