Need to pop the cover off the main breaker panel and use a clamp-type current meter to see which circuit(s) are using power.
Or hire an electrician to do it, if you aren't totally confident in your ability to do that safely.
Or hire an electrician to do it, if you aren't totally confident in your ability to do that safely.
Entirely reasonable to be quite afraid of it - it’s a good way to get killed if you aren’t very experienced around somewhat high voltages (240v).