Work on fixed installations (faste installationer) has to be done by an autoriseret elinstallatørvirksomhed (authorised electrical firm). Ask whether they hold the authorisation themselves or bring someone who does, and get that on the invoice.
Odense covers the centre and housing areas in Odense C, N and Årslev. Drives on Funen are often shorter than in the capital, but older houses with a basement and a narrow drive can still add time. The same 1 businesses as the Danish page: Odense El ApS.