1995 Chevy Camaro

My 95 camaro won't start. It has had this problem 2 other times. The first time, I went to start it and there was no dash lights, but it acknowledged that the key was in the ignition by beeping and the radio worked. We towed it to the mechanic and he replaced the starter and it worked for 2 days then wouldn't start again. When we went to tow it the next day, we tried to start it one more time and it started. I drove it to the mechanic and he replaced the ignition switch and some ignition wiring. After this, it worked for a month. Then yesterday, I went to start it and nothing. The radio lights wouldn't even come on anymore. I did notice however that when I turned the key back and held it hard, the radio would start. So it seems that it is something electrical