SantaUK wrote:
I want to fit lights under my kitchen cabinets and have found some good
mains ones at TLC. I want them to operate whenever my cooker hood is
opened. I remember from my car days of using relays to work other circuits.
I can tap into the light circuit of the hood, so where could I get a
suitable relay that will operate the mains lights?

http://www.maplin.co.uk/
http://www.cpc.co.uk/
http://rswww.co.uk/
http://www.farnell.co.uk/
http://www.theonion.com/

Should keep you busy for weeks.

Alternatively, investigate the switch rating on the cooker hood,
it may be adequate.