there are pressure switches for 120 volt pumps ,yes????are they cheaper than 240 ones??

I purchased the house new 6 years ago - I always had a pump but don't recall the frequency though if I had to guess I would say 4-5 times / hour. For the past few months it has been running more frequently. It now runs every 25-30 seconds. My pump is a large pump and I would say pumps about 3 gallons of water every 30 seconds just by seeing the water enter and exit. I thought I might have a water leak so I compared water bills with my neighbors and they were about the same. I also checked the crock water for chlorine and fluoride and didn't find any. Just to be safe, I had the city come out and check for leaks before the meter but everything looks good. I then had 2 different plumbers to have a look and see if there was anything wrong. They both said it appears things are working and blamed it on the high water table - I live in Grand Rapids, Michigan. They both recommended I replace my battery backup system with a water commander - water powered system but for $2,000 I chose to keep what I had. I then called the county drain commission to see if the storm drain was clogged or if there was a leak - thinking I might be getting excess water because the drains around the house are not working properly, plus my sump pumps into the storm drain. The storm drain is behind my house, pump is in front and storm drain runs from back to front, under road and into a creek which is higher than normal. I am out of ideas - I am planning on dying the water in the storm drain and see if the dye ends up in the sump crock. This will tell me if there is a storm drain leak and I am recycling but I don't think so. I am looking for another solution and am fresh out of ideas. I want to reduce the amount of water - possibly a different drainage solution which doesn't require water entering my basement and me pumping it out. The current solution requires +$100/month in electrical costs plus poses a serious risk should I lose power for a long period of time. Any suggestions would be greatly appreciated.