First, ensure that all switches are off before you start removing the paint. If the paint splatters are recent, they can be cleaned with a cloth soaked in warm water. If they have already dried, scrape off with a paper cutter, after first wrapping its blade in a cloth to prevent scratches from forming. Do not use any strong solvent as it may damage the plastic surface of the panel. Do not switch on any fixtures till the board is dry. You can also use mineral turpentine oil to remove paint from glass and steel. Do note that the recommended method for painting involves proper masking of light fixtures and other elements in the house to avoid such problems.