Hi there,
There are many electricians listed in the local yellow pages - so a thumb through that could be your first step - have a look on Yell.com as well.
However, as I've recently needed an electrician - and with the current economy as it is, and tradesmen short on work and taking on almost anything that comes their way, you have to be a bit clever in order to get a good deal.
I did the following
Go to ratedpeople.com - here, you enter a brief description of the job you require and local trademen will respond to you. I got a call from a local electrician company and they said they'll come out later that afternoon for £83+VAT plus any parts prices needed. I said thanks but I'm not paying that amount for the type of work I wanted to do and I'll continue looking. F.Fwd 3 hours, and they called back saying they'd do it for £59+VAT plus parts prices. Again, I politely declined. In the meantime I was looking into how to do it myself, but told them I was talking to other electricians etc as well.
By 2pm they called back again and said they do have an engineer slot available - and should we go ahead, so I said, if they do me a deal right now at £50 inc VAT I'll be there in 20 minutes, they agreed. I got the heater looked at and realised it wasn't worth fixing. Whilst I had the electrician there I got some other minor electrical bits looked at.
So, I was happy with a 50% reduction in price that I 'wangled' out of them, I had wanted a simple check only and really only wanted to pay £30 but with my tenants wanting it done I had to move quickly. Please do the same as installing fanlights, is relatively a straighforward job for these kinds of people. Hopefully, you'l be able to 'wangle' a discount in the same way I did!
Good luck! DtM! West London & Slough UK!