Hire yourself out to pick up dog poop in people's yards.
Buy some number stencils, some white paint and go to neighborhoods. Charge people to paint their number address at the end of their driveway or curb.
Go to the Goodwill and buy games that have game pieces. You can sell the 'parts' like in monopoly and the game board separately for replacement pieces.
You can buy some small appliances and canabalize the appliance and sell 'parts'. Like for instance if you have a food processor, you can sell the blades, the container, and any other accessories individually. Electric skillets you can sell the electric cord with the heat control. You can sell the lid handles for replacement. Percolators, you can sell the coffee basket, lid and even the coffee maker without the accessories. Keurig coffee makers, sell the water container, the drip catcher and anything else you can yank off it. Washing machines and stoves, you can sell the knobs and the iron grids off of gas stoves. Most new stoves do not sell broiler pans, you can sell those. Before you throw anything out think canibalization. What can you remove from it and sell? Some doorknobs are unique like glass ones.
There are lots of replacement parts people are looking for rather than buying a whole new appliance.
Be a house sitter when people go on vacation.
If you are a handy guy, drive around some rich neighborhoods and find mailboxes that have become eyesores or never installed in the ground correctly. Leave a message in a plastic bag meant to hang of a door knob and tell them you are in the business of installing mailboxes and if they would like to have a new one installed. You could put some examples (pictures) of types of boxes and types of post you would use. Give a "starting at" price like $99. Then if they choose a more expensive type installation price it as necessary. Do you homework and become an expert on boxes, posts and costs.
You could become a personal cook and go to a person's home and cook up a weeks/month worth of dinners. You would have to be a fairly good cook. I would suggest that you put together a monthly menu, 5 days a week. You could buy some freezer recipe books that tell you how to prepare, freeze and cook/reheat the food. You would go to their house and cook up the food, package it up and freeze it. Then have the name of the entree with the instructions. In most states you have to have a licensed kitchen to prepare foods but you can go to a person's house to prepare foods without a license. Another option would be to rent out a licensed kitchen at a place like a church, grange, restaurant. There are books on how to cook for a day, eat for a month.
If you are good at sewing, you could consider alterations like hemming pants, taking in waists, shortening jacket cuffs.
If you can play an instrument, you could teach musical instruction, piano lessons.
Teach an adult education class. You don't necessarily have to be a teacher but if you have a hobby or are an expert in some area, you can charge each student a fee to get instruction. Could be jewelry making, Excel, Word, Powerpoint, learn about Medicare, Social Security, Real Estate, sewing, exercise, dance, horticulture, etc.
You could advertise to scan people's photographs on a thumbdrive so they can downsize. Offer different packages like $99 for 300 photos including thumb drive. $199 for 600 pictures including thumb drive. Include some kind of a decorative box or key chain to keep it from getting lost.
How about a party bus! Rent a luxury bus and plan day events for seniors to go out to lunch, tour a vineyard, a zoo, an aquarium, a museum, dinner theater, lobster fest, casino, culinary school, scenic places. Costs would have to be calculated.