My darkroom is in the laundry (Dust is a problem!) I am in the midst of re-wiring the house (it had the dreaded aluminum wire). Here in the US we have to use GFCI (ground fault circuit interrupters) on the counters and within six feet of a sink. The problem is that the new GFCI's are equipped with LED lamps. Now I bought two major brands, Leviton and Cooper. The Leviton is totally unusable in the darkroom. It has a green LED that lights all the time, that one went to the kitchen. You might put a dab of paint on it but unless it is black the lamp will probably make the faceplate glow around it. The Cooper model is what I installed. It has a yellow LED but it only comes on during a ground fault. The light extinguishes when it is reset.
I did look at Leviton's catalog and they do make a model without the LED. Lowes and Home Depot don't carry it but one could probably get it from an electrical supply house. Hubbell also makes GFCI's but I didn't check to see if they made one without the LED.
We should all have the GFCI receptacles. If you have wet hands (like I often do) and touch the timer or enlarger there is risk of electrocution.