Schedule of Financial Information Relating to Industry Segments (Details) - USD ($)	3 Months Ended		9 Months Ended
	Jan. 31, 2025	Jan. 31, 2024	Jan. 31, 2025	Jan. 31, 2024	Apr. 30, 2024
Segment Reporting Information [Line Items]
Total net revenue	$ 4,912,000	$ 5,394,000	$ 16,306,000	$ 16,175,000
Total income from operations	1,196,000	1,518,000	4,453,000	4,674,000
Total depreciation and amortization	120,000	123,000	363,000	364,000
Total capital expenditures	51,000	20,000	359,000	263,000
Total assets	63,724,000		63,724,000		$ 60,780,000
Security Alarm Products [Member]
Segment Reporting Information [Line Items]
Total net revenue	4,406,000	4,939,000	14,642,000	14,627,000
Total income from operations	1,073,000	1,373,000	3,994,000	4,226,000
Total depreciation and amortization	54,000	55,000	162,000	146,000
Total capital expenditures	51,000		196,000	224,000
Total assets	14,892,000		14,892,000		15,263,000
Cable & Wiring Tools [Member]
Segment Reporting Information [Line Items]
Total net revenue	335,000	332,000	1,092,000	1,117,000
Total income from operations	81,000	105,000	304,000	323,000
Total depreciation and amortization	30,000	30,000	91,000	91,000
Total capital expenditures
Total assets	1,966,000		1,966,000		2,082,000
Other Products [Member]
Segment Reporting Information [Line Items]
Total net revenue	171,000	123,000	572,000	431,000
Total income from operations	42,000	40,000	155,000	125,000
Total depreciation and amortization	24,000	24,000	73,000	61,000
Total capital expenditures		20,000	21,000	20,000
Total assets	870,000		870,000		859,000
Corporate General [Member]
Segment Reporting Information [Line Items]
Total depreciation and amortization	12,000	14,000	37,000	66,000
Total capital expenditures			142,000	$ 19,000
Total assets	$ 45,996,000		$ 45,996,000		$ 42,576,000