Well, I am looking for universal solution if possible to get visual control of all sorts of motors and appliances (garage doors, watering system, etc.) remotely. In this particular case I have a sewage pump that has this float switch, which switches it on and off. However all this equipment is situated around 30 metres away in the backyard and I want to monitor it in the house. Although this float switch seems to be quite reliable, on a couple of occassions something went wrong and the pump kept pumping semi dry. I was lucky to notice it quite soon to stop it, but you can't expect to be lucky for a long time
Therefore I thought I'll get advise in this forum. But it looks like there no simple and cheap solution. I thought there should be schematic in place that starts drawing small current from the mains to lit up an LED as soon as the main appliance starts using current. Maybe using neon indicator is the simplest way to go forward.