You could try doing a google search using the words "science fair project" and one of the 4 subjects listed in your first posting (above). This may give some good ideas where to start and what you might be interested in. Be sure to come up with your own original question and do some background research before you actually start your experiment.
We were thinking of making shaded contacts (like sunglasses, except contacts) for humans, or reseaching if dogs/cats could wear glasses or contacts to prevent blindness. Do you think that these ideas would be good for science fair?
I would suggest using the Topic Selection Wizard to help you choose a topic that is at the grade 9-11 level as previously suggested by candicebrownelliott2. Or maybe searching the web for projects in the area you are interested in to get some ideas. Why don't you go back to your original area of interest of electricity/electronics?