Start with your neighbors. Does anyone else have the problem? If it is electrical, they presumably would have the same problem if they are on the same panel as you.
they may also have solved the problem. Ask the doorman...he may know what the prior occupier did.
Is this the same kind of lines that can occur if someone plugs in a vacuum cleaner and starts using it?
they may also have solved the problem. Ask the doorman...he may know what the prior occupier did.
Is this the same kind of lines that can occur if someone plugs in a vacuum cleaner and starts using it?