I bought 4 ESP8266-01 for $8/DKK50appr (the smallest version) and some Wemos D1's (3 for GBP7.86/DKK65appr on ebay.
So now for the testing
The 01 boards are not that simple to program. You need a special programmer (which I also bought on ebay). In the meantime I programmed the Wemos D1 directly from the Arduino environment, connected with a USB micro cable. Next was to test it, so four LED's were put on the bredboard, and the Blink testprogram loaded (copypasted LED ON/OFF and delay between). Everything worked beautifully. So a relay bought on ebay (1 channel relay) and attached, wires connected to a lamp.