What can I use to filter out all kinds of different noises and interference's coming from the AC line wall socket into the bench test equipment. If I plug my PC laptop switching power supply in the AC line wall socket, the switching will be picked up on my bench power supply and oscilloscope. I have to turn off the lights on the workshop because there is noise ,interference, high frequency spikes. I have tried EMI/RFI filters, line conditioners and used an Isolation transformer, they help some but still noisy and high frequency spikes when lights are on and if I have switching power supplies plugged into other AC wall sockets. What can I do to solve this problem?