If you are in the Fort Myers area, you should really put this on your list. It's open all year during the day but during the Christmas season, they decorate the property with beautiful Christmas lights (invented by Edison) stay open until 9:00 PM and have evening guided tours which offer a whole different perspective. You can do a self-guided tour for $15 per person, but for $5 more I would recommend the one hour plus guided tour. The guides are very knowledgeable and entertaining. During busy times, you may want to get there well before tour time because they limit the number of people they take on the guided tours. There's also a "behind the scenes" tour in the morning that sounded interesting. Might try that next time.
You will see Edison's winter home and adjacent guest home with original furniture, You can't go in but everything is visible from the outside. Henry Ford was a buddy of Edison's and bought the house next door and you can visit that as well. Some Ford vehicles from the early days are on display. The grounds also contain Edison's lab and other buildings as well as a museum. For plant lovers, there's an amazing collection of tropical plants on the grounds that Edison collected over the years.
Nice way to spend a couple of hours and learn about some fascinating and influential people who had a huge influence on how we live today.